What do you consider as the best way for resolving the nationwide housing crisis?

Yes, the places where people have jobs. Port Glasgow is not the only place in the country. The millions of people who have jobs elsewhere and are looking for a home to buy cannot suddenly pack their bags and move to Port Glasgow en masse, their job can't move with them.
People live where there is work available and, yes, I think this is broadly a national crisis. I used the South as an example as it is the most obvious one, you aren't going to find < £60,000 homes there very often (if ever).

Obviously build more: we need to densify our cities and their inner suburbs, and make it easier to build houses than it currently is. I'd move to a deemed consent model where if a planning application fits the local authority's development plan and rules, it has to be built: no objections from the community. We need to get better at building infrastructure, particularly reservoirs, to let us do the housebuilding in the areas where it's required. The market is pretty good at adjusting house prices based on supply and demand, so increase supply and prices should fall, and some of the unusually cheap properties being touted above will be cheap due to low demand (for a reason!).
It'd be more marginal in terms of impact, but on the demand side I'd require planning approval to change a property from a primary home to a second property (either empty for the owner to visit occasionally or to rent out as a short-term holiday let): cap the percentage of second properties at say 20-25% of a community and then require primary homes to be either owner-occupied or let out on a long term basis.
Don't necessarily believe that foreign students are a huge driver: I don't need to look very far in Cardiff to see that there are whole new accommodation blocks being built to accommodate foreign students, so increasingly (given that we tend to only get wealthier overseas students given the size of the fees!) they're not part of the demand for traditional houses and flats. Also, we're far from the only country in Europe to have high levels of immigration (student or otherwise) but few other countries seem to struggle to house their populations quite like Britain does.

Here's one in Bodmin
https://www.rightmove.co.uk/properties/139497035#/?channel=RES_BUY
Bodmin was my first search...
Again, rather be closer to the sea? How about Plymouth?
https://www.rightmove.co.uk/properties/144733502#/?channel=RES_BUY
Would rather be south east rather than south west? Folkestone...
https://www.rightmove.co.uk/properties/148208198#/?channel=RES_BUY
I'm not sure if we have an office in Folkestone, but I could move with my job to Bodmin or Plymouth.

These are, again, not homes representative of the wider national picture. Bodmin and Folkestone aren't particularly well populated areas with tens of thousands of jobs going. Plymouth is perhaps your best example but this is A) a 1 bedroom flat and B) covered in mold...? It's not suitable for anyone to live in, let alone a family.
Here are some other examples:
Bristol £289,000: https://www.rightmove.co.uk/properties/151581764#/?channel=RES_BUY
Portsmouth £250,000: https://www.rightmove.co.uk/properties/150792620#/?channel=RES_BUY
Reading £440,000: https://www.rightmove.co.uk/properties/149609816#/?channel=RES_BUY
Slough £350,000: https://www.rightmove.co.uk/properties/151637618#/?channel=RES_BUY
All two bedroom, terraced properties with barely any front / back garden. All well outside their respective city centres. All in reasonable condition (by the photos) but none of them extravagant. All ridiculously expensive.

'The wider national picture' isn't of people fearing homelessness.
Yes, more expensive properties are available, ours cost us £545k in Oct '22 (plus LBTT). Quite affordable for us in our 30s, working in the public sector without the help of 'the bank of mum and dad'. People are paying these prices as its quite affordable for them. There are cheaper places to live which are affordable on NLW.
If I were fearing homelessness I'd set my expectations lower. I wouldn't be expecting to live in a detached five bed half an hour walk from the centre of the third most populous city in the country.

So that makes it okay? 'You aren't homeless, what are you complaining about?'
The homes I listed are not affordable for most people, least not with the bank of mum and dad or many years (if not decades) of saving.
Home ownership has gone down each generation. That is a problem, it means far more people are trapped in renting hell and will not have the security of owning their own home.

Surely to the OP fearing homelessness then yes?
'Home ownership has gone down each generation.' - surely not? It was 25% in 1918. Isn't it over 50% now?
https://www.historyextra.com/period/modern/a-brief-history-of-home-ownership-in-britain/

Home ownership has gone down for each generation since the 1950s.

He also isn’t aware that half of the Scotland’s population lived in council housing in the early 1980s...

Also chose 1918 as a point of reference. 🤦*♂️

Home ownership has gone down for each generation since the 1950s.

Also chose 1918 as a point of reference. 🤦*♂️

Someone with too much spare time on their hands is trying to be contrarian.

So it's gone down over the last three generations. The lifetime of Kier Starmer.

Is £65-70k for a two bed freehold property really out of your affordability?
https://www.rightmove.co.uk/properties/150889244#/?channel=RES_BUY
That's what - 2x to 2.5x the average wage in the UK, about 1.5x average household income.
You don't want to live in Port Glasgow?
Then could go for somewhere more rural, get a bit of a sea view, under £50k, again two bed freehold.
https://www.rightmove.co.uk/properties/126593144#/?channel=RES_BUY
Don't fancy living in Scotland due to the advanced tax band? Then how about a three bed terrace for £50k?
https://www.rightmove.co.uk/properties/150987767#/?channel=RES_BUY

No the point would be to stop a handful of people buying up all available housing, driving up the cost of houses, while also driving up rental rates. Because the point is none of them can afford these places themselves, they can only "afford" them by having their tenants paying the mortgages for them.

I agree with Hotpud that the solution lies in building more houses, but let's not be fooled by the apparent simplicity of this suggestion. The devil, as they say, is in the details. How do we go about building these houses? Should they be private developments, social housing, or a mix of both? If we lean towards social housing, which many argue is sorely needed, how will we fund it given that the public purse is already stretched thin? It's all well and good to say "build more houses," but we need to address the underlying mechanisms and financial realities.
One potential route is to incentivise private development, perhaps coupled with rent caps to ensure affordability. However, this raises another question: what do we do about landlords? The current state of landlord regulation is often criticised for being too lax, allowing for exploitative practices that exacerbate the housing crisis. Should we consider stricter regulations, or even more radical solutions like rent controls or limits on the number of properties an individual can own? These are the kinds of questions that need addressing if we are serious about resolving the housing crisis in a sustainable and equitable way.

Obviously build more: we need to densify our cities and their inner suburbs, and make it easier to build houses than it currently is. I'd move to a deemed consent model where if a planning application fits the local authority's development plan and rules, it has to be built: no objections from the community. We need to get better at building infrastructure, particularly reservoirs, to let us do the housebuilding in the areas where it's required. The market is pretty good at adjusting house prices based on supply and demand, so increase supply and prices should fall, and some of the unusually cheap properties being touted above will be cheap due to low demand (for a reason!).
It'd be more marginal in terms of impact, but on the demand side I'd require planning approval to change a property from a primary home to a second property (either empty for the owner to visit occasionally or to rent out as a short-term holiday let): cap the percentage of second properties at say 20-25% of a community and then require primary homes to be either owner-occupied or let out on a long term basis.
Don't necessarily believe that foreign students are a huge driver: I don't need to look very far in Cardiff to see that there are whole new accommodation blocks being built to accommodate foreign students, so increasingly (given that we tend to only get wealthier overseas students given the size of the fees!) they're not part of the demand for traditional houses and flats. Also, we're far from the only country in Europe to have high levels of immigration (student or otherwise) but few other countries seem to struggle to house their populations quite like Britain does.