Jim's idea is similar to one I've been mulling over (2 of my boats were Mulls - "mulling" is something I have a lot of experience with). Begin with a shorter version. Put in at a Marin County location. 1) Loch Lomand where parking might be a issue - although there is on-street parking nearby -- or 2) Buck's Landing on Gallinas Creek in Terra Linda. I'm headed for Terra Linda this weekend by car and plan to check out Buck's for putting in and for parking. It's about a mile north of China Camp. Water depth might be an issue at low tide, although the morning low is 2.9 at the Golden Gate (08:19).
From the Marin County launch site to the VYC day #1. It's a fairly short hop over to the bight between Pt. San Pablo and Pt. Pinole and then up to Carquinez. Or, take the norther route around the top of San Pablo Bay (something you can't do in a convention sloop). Overnight at the VYC. Perhaps "camp out" on the south deck? But Jim's idea offers an alternative - below.
My idea was day #2 up the Napa River to either the Napa Valley Marina or Napa launch ramp further up. Might even be possible to get the Napa YC involved?
Jim's idea about the Vallejo 1-2 weekend has merits. Company on the way up. Since it's singlehanded up, spare bunks on SSS boats overnight at the VYC? And his bungalow is really nice - as it his significant other.
A possible problem is the Sunday morning ebb (1.4 knots). Slack's at about 10:30, so a delayed start could ride the 2.3 knot flood in the afternoon?