As much as I hate to say it, I don’t think that it makes much sense for the main hub of the rationalist movement to move away from Berkeley and the Bay Area. There are several rationalist adjacent organizations that are firmly planted in Berkely. The ones that are most salient to me are the AI and AI safety orgs. You have OpenAI, MIRI, CHAI, BAIR, etc. Some of these could participate in a coordinated move, but others are effectively locked in place due to their tight connections with larger institutions.
I think that more creative options need to be brainstormed and explored to deal with the situation in Berkley.