Kalle, I was a bit hesitant to post here because, well, our boat is headed down to the Bay this summer and we've been doing this exact dance. Selfish - I know. But,,,
Richmond Marina Bay Yacht Harbor has a 50' and a 60' end-tie available for immediate move-in.
Berkeley Marina has a 50' and a 52' available for immediate move in, with the caveat that the 50' is part of their next dock
replacement section so will be without power later this year and you may have to move for a while.
Alameda Grand Marina has a 70' end-tie but won't put anything wider than 25' on it. Only available for 3 months (not a permanent home).
The City of Oakland marinas
have had two cat spots (mid 40s) empty as late as last month (have not checked recently).
Alameda Ballena Bay has ~400' of side tie used for transient berthing that they are willing to rent for permanent berthing. $$$$ (most expensive we found).
Alameda Marina Village, Alameda Marina, and Fortmann all reported no spots.
Wasn't looking outside the Easy Bay, but from that sampling it is not impossible (at the moment) to find a cat berth.