My DS's partner is currently in his first year at Cornell studying for a PhD (as you mention Ithaca, I assume this is where your DS has a place). He is renting privately a 2 bed furnished apartment that overlooks Ithaca Falls and pays US$1300 a month (includes all bills). His block has lots of PhD students living there and is a short walk to the University, but a fair way out from the town/shops.
In his first year his funding comes from a 'scholarship', which is taxed at source in the US. However scholarships are tax free in the UK, so my understanding is he will do tax returns in US and UK and hope to get the tax refunded. When he spoke to SLC they advised he is still considered to be 'studying' and will not need to make Student Loan repayments.
In subsequent years, his funding is effectively 'pay' for teaching or other work, so he is assuming he will be taxed.
F1 visa wise, the form is quite arduous but once completed he was not asked to attend an interview at the US embassy (I am not sure why!) and he receive his Visa within a week. In fact, they have just got married and my DS now has an F2 visa and that was all done and dusted within 10 days (including attending an interview at the US embassy)
Be aware that your DS will need to be fully vaccinated. This includes proof that he has had chicken pox. If he has not had that or is missing any, do not worry, he can be vaccinated when he arrives there, for free or very little cost.
Cornell will only pay the stipend into a US bank account, so get one set up as soon as possible. He will actually need to be in the US to do this.
The PhD cohort are very international there, with few US students and he has yet to meet a fellow UK student. In fact at a welcome event with international foods, the UK was represented by a packet of digestives (which nobody ate!)
They have used Norse airlines when travelling to/from UK, its cheaper to book it from their US website and as they do not have luggage they have got return flights for £300. There are coaches to NYC, take 4 hours and costs c£40 one way.
The health insurance coverage is very, very good. The cost of food is very, very high in Ithaca (unless you live on a diet of pizza), fruit and meat particularly so. And finally the buses are free for students in Ithaca :-)