Can I still salvage this relationship?

You should ask him (not us) if it’s worthwhile for you to consider transferring. If he’s a good guy, he’ll tell you the truth about if he feels you have a future together and give his opinions on you moving near him.

I would say that for your own considerations… if your program is for several years, there’s a chance he may not stay in California that entire time so even if you move you may have the same problem again in a year or two. It’s also an enormous amount of work plus it will interrupt your program to transfer. So you should evaluate if you’d really want to move or if you already chose the best program and location for yourself. If it’s not more for you then, ‘I already put hard work into getting to this program’ and you don’t really care specifically where you are located as long as you’re on track for a PhD, then it’s worth considering a move if there’s a future for the relationship. But he’s also known you were going to start classes in the UK in person eventually and didn’t discuss planning his career around the relationship or looking for jobs near your campus. So if it’s really a sacrifice for you to transfer, and he’s not interested in thinking about your logistics (like some couples take turns choosing where to live or whose career / education to prioritize), then take into account if the right relationship for you is one where you haven’t been working together as a team to make things work.

Also, to be fair, travel is very complicated right now and constantly changing with the pandemic. So it’s not surprising that he’s having second thoughts as the distance becomes less theoretical. It may end up being bad timing and difficult logistics and not even about the relationship itself.

Good luck with whatever you both decide!

It’s an unfortunate situation, but if that’s what he has to say about it, you should be refocusing on yourself. It sounds like he’s aware of what I was kind of calling him out on (he knows it’s uneven for you to drastically adjust your life plans for him when he didn’t make moves to do the same for you). And 4 years of long distance, 8 time zones apart, during a pandemic which makes travel difficult… it’s a very big ask during a time where having any physical affection in your life, even platonic, is already diminished (for anyone socially distancing at least). The situation would wear on anybody. And not just on him, on you, too!

I think he’s telling you he’s not willing to put in the effort required, which is why he can’t ask that of you. And he shouldn’t ask, because you can’t put the entire weight of the relationship only on your own shoulders. Plus, as also said by other posters, you shouldn’t give up your own path for a guy… when it is right, both people have aligned goals and make them work together.

FWIW, it sounds like you have good friends. They’re giving good advice and sound supportive of YOU, so continue turning to them if things don’t work out.