Im in the same area as you. I'm in the east bay, hayward to be exact. I haven't had any cold problems yet but I am also minutes from the bay. I am currently fruiting a Blue Java ( confirmed on here ) in a 65 gallon, which my guess is bigger then you want to do. I have the 65g sitting on plastic pallets and using webbing to strap down to the pallets to help support the weight if we get strong winds, so far so good.
