Falmouth glasney shared room

Anyone know how long it usually takes to move into your own room from a shared one? I've been given my absolute last choice of accommodation and honestly would rather defer and rent privately next year than live the full year in shared. I've even asked if I could have a study bed room to myself until something frees up but they basically said "too bad can't do anything until you get here"

I'd also feel really bad for the person I'm put with and wouldn't want them to feel bad if I immediately say I want to move rooms. :/

Rooms tend to free up a few months in, from what I have heard people don’t find sharing a room as bad as they think and a lot of people stay really close friends with their old roommate even after moving to a different room!
I believe having a shared room to yourself at the start may be reserved for students with medical needs who weren’t able to get a single room on their own and are physically unable to share but on moving day if your roommate doesn’t turn up (and has no intent of moving in) then you can agree to pay the price for a single room instead of shared and keep it to yourself (I think)

Would food allergy's be considered a valid medical reason? I was initially anxious about sharing a kitchen because of this in case people didn't clean up, but a bedroom seems even worse to have to ask someone to not eat something altogether.