Well, decision day came and went, and I have a chronic inability to make decisions, so here's the deal:
I'm coming back to Glasgow.
I have an office in Glasgow, the money comes centrally from the AHRC so that's not a problem, and I'm teaching at Glasgow with my supervisor there. BUT, my second supervisor is at Oxford, so I'm spending one term in three (Trinity) in Oxford with the other two in Glasgow, and I'll retain the title of 'recognised student and associate of Balliol College' throughout my doctorate. So I get to keep ties and supervisors with both, but get to live in the better, cheaper, city on the same salary, and will amaze all the freshers with just how little a PhD student with two degrees actually knows about history and/or economics. It'll all be a horrible mess, but I have an office. And I'll be a freshers helper again. And I get to have £1 drinks again. Boo to the ya.