I basically told them I was researching AI safety, and could point to a handful of relevant books which I genuinely wanted to read, which were in the Bodleian but not in e.g. the county library. I think you can search their catalogue at https://solo.bodleian.ox.ac.uk even without an account, which is quite helpful.
Common Ground on Little Clarendon Street is a good shout in the meantime, and the Country Library in Westgate is a decent change of scenery.
You're very welcome, I'm glad you like it :)
It possibly worth me mentioning that my level of transience is pretty whole-heartedly chosen: I gave up job stability for this (startup was successful). I picked 6 months because that seemed like a good amount of time to explore the possibility of doing this for longer, I considered applying for 12 months (which I don't think would have negatively affected my application) but mainly worried about over-committing. I know people at TH who have 4 year contracts, which I'd consider relatively stable.While I live on a boat, the boat doesn't move that fast & I'm planning on Oxford being my UK base for the next decade (with some months abroad). Health insurance is a non-issue here, and since I now own the boat I don't pay rent either. So I feel pretty stable, really, even though my home sways when the rowers come past.
The book, in case anyone is wondering, is The Art of Community by Charles H. Vogl, and is very good. I'm grateful to the CEA.