CA #1 is one of the most beautiful roadways in the US. Big Sur should be on every traveler's list. You shouldn't have any issues towing up to SF, other than the limited amounts of parking and pull out spaces along the highway.
If it was me, I'd probably get off South of SF and take 101 North to some point like San Rafael or Santa Rosa and then head back West to the coast to continue the journey on #1 North. You'll miss Muir Woods and Stinson Beach but the inland drive will save a lot of hassle. Also, the route back West through Russian River is a very scenic trip in itself.
Good luck and enjoy the trip!
