I think Shelter Cove (0Q5) is a nice place to fly into on the Northern CA coast although I haven't been there. It can get fogged in a lot too. I fly out of Livermore but haven't ventured North. Don't forget to fly a tour of the Bay Area as you leave.
Fog is much less of an issue over the coast (in SF, at least) in September and October so you picked a good time from that point of view.