Your driving options are (1) a boring, ugly 8.5 hour drive up the middle of the state on I5, or (2) a beautiful but slow 12-15 hour drive along the coast.
We did SD-SF in 3 days, stopping at every burrito/wine/vista point in between. Definitely not the drive to make with a timeline though.
from San Francisco for a day or 2.
Highway 1 (Pacific Coast Highway) doesn't go near the coast at all between Gaviota (just west of Santa Barbara) and Pismo Beach. I don't think that stretch of Highway 1 away from the coast is anything special, but you'd be going a lot slower than you would on 101 or 5.
The traffic is not predictable in the least and a 7 hour drive can very easily become a 10 hour drive depending upon when you are hitting LA or the Bay Area.
Do all that fun stuff on another trip.
can be gorgeous if you drive up the coast. You could do Hwy 1 through Santa Barbara up past Morro Bay. Hwy 1 past Sam Simeon will still be closed, so you 'd have to cut over to Hwy 101 via the 46.
If your plan is to drive Interstate 5 the entire way, I would recommend flying. There are some really cheap flights from San Diego to the Bay area. Plus you'd save the money on the rental car fee for returning the car to a different airport.
as someone who just did the LA - Bay Area drive on the 5 twice last week.
It's always sort of fun to hit the Grapevine when driving south, but it's merely a convenience route and can't compare to driving the coastal route. Unless you really love playing the pass the semi while the Mercedes SUV tries to cut you off game over and over and over again.
It would be a beautiful drive for the most part, but it wouldn't be nearly as enjoyable if you didn't have time to stop and do some exploring along the way, in my opinion.
If you're just doing it for the scenery out of the car, it's going to be a lot of work/driving that I'd probably save for another visit when you have more time.
Agree that driving the coastal route is the only way it is worth it, but it would be a grueling day (8-9 hours with no traffic and no stops), and there probably wouldn't be much time to stop and see stuff.
If they were willing to spend a night halfway up, that would at least let them stop along the way to see a few places.
Unfortunately, they involve crashing down the cliffs and into the ocean below.