SF Bay Area Winter Soaring

I'm going to be in the SF Bay area for a conference in January 2008 and
I'm pondering the idea of taking some time afterwards to do some flying in
a new place. I'm looking to rent a glider and stay for a couple of days. I
have some questions for people familiar with the area:

How is the soaring in January? I assume the thermals are about as dead as
they are here in Virginia, but here it would be good wave/ridge season, is
that the case there?

How long should I expect to stay to have a good chance of seeing some good
soaring? Obviously nobody can predict the weather with great accuracy that
far in advance, but some vague idea as to how frequent good soaring is
during that time of year could be helpful. I have a feeling that staying
just for the weekend following the conference is being too optimistic.

What is a good operation in the area? I recall from previous looks at the
SSA's map (which doesn't seem to work for me now, it sticks on "Loading
soaring sites for State..." when I click on a state) that Williams Soaring
looked like a nice place and reasonably close. I'm open to clubs but it
seems to me that for this sort of transient thing a commercial operation
might be a better choice.

I'm a low time pilot (under 40 hours, checkride passed in April) and so
far I have only flown with my club, what should I expect or prepare for
flying elsewhere? Renter's insurance is the obvious one and I'll search
the group archives for advice on that, anything else I should know?

Thanks in advance for any advice.

--
Michael Ash
Rogue Amoeba Software