If you are in the East Bay, check out Rates - The Wine Chest. A number of folks have used them for “short term” bulk storage while they build their cellars. Have seen them come and go. Ask for Joe.
Subterranean (is Joe still there?).
I keep my stuff at Vinfolio because I need the shipping/mgmt services since I no longer live locally in CA.
(I lost some $ on prepaid storage when they went BK more than a decade ago iirc, but vinfolio has been just fine for me since)
I actually just got a tour of K&L’s SF lockers this week. Fair amount of availability, and their prices seem fair if you’re based in SF.
I use K&L in RWC.