To get from Hwy. 101 to Hwy. 1 your best bet is probably Railroad Ave., Stoney Point Rd., Roblar Rd. & Valley Ford Rd. (see Google map) This route is the flattest and straightest.
http://tinyurl.com/3qsj8ob
Just North of Santa Rosa you can pick up River Rd./Hwy 116, but there are lots of towns & traffic as Russian River is a popular vacation/resort area.
Even further North is Stewarts Point Skaggs Spring Rd. that runs from Healdsburg to the coast, but this is NOT recommended for towing as there is lots of elevation change and most of the road is very narrow and twisty. Highly recommended for sports car or motorcycle travel, it's one of my favorite stretches of asphalt on the planet!
No matter which route you choose please pay attention to your rear view mirrors and take advantage of the many turnouts to allow faster traffic to pass. I do a fair amount of recreational driving/riding in Sonoma and Mendocino Counties and nothing is more frustrating than coming up behind slow moving vehicle who's driver refuses to take advantage of the turnouts as legal passing zones are few and far between...
Looking forward to meeting up with y'all sometime mid-day on Saturday, have a safe and courteous trip to Ocean Cove!
Regards-HW