Help - Min. Tenancy length renting as an international student

Hi, for context Im an international student currently studying in London, i'm looking to rent from sept 2025 onwards but i won't be able to stay in uk for summer. My first dilemma is that lots of the properties (even the student friendly ones) i've looked at on rightmove usually say 12months minimum tenancy length, and the short lets are too short. My second dilemma is that I have exams soon in may and june, and i'm leaving uk on 21st june, not returning till after summer so i've been contacting agents to arrange viewings, but one of them told me usually current listings look for people to move in from 2-4weeks, and if im looking to move in on sept 2025 i should look at properties during July (which is when i'm not in the uk), hence i'm trying to book viewings during this time frame (april-june).
I've looked at zoopla but i cant seem to find the details of tenancy length on listings.
And also! If anyone has general advice on what to note down during viewings that would be helpful. So far i assume i should generally look for transport and grocery convenience and natural light?
Any advice would be much appreciated! I've never rented before so forgive me if I need more clarification :smile: