Sounds fun! You could take 128 off 101 at Geyersville which will take you through "Wine Country", Calistoga, St Helena, Napa, etc.... It is a bit windy at first, not extreme, but it mellows out. It will also add travel time to your trip, but it is scenic. If you like wine though, it's worth the extra time. I've only done it in a car, so I don't know if it's RV rough. It eventually turns into 29 which ends at I-80, hit I-880 in Oakland (just keep going) and you'll connect back to 101 in Santa Clara/San Jose, aka "Silicon Valley".
2015 Forest River FR3 30DS - No Ragrets
Toad - 2011 Jeep Wrangler