There's just one other anecdote that I'll add to this... I've found it a lot harder than I expected to get good shots close to sunset. That's not because of my equipment, rather that the atmosphere just doesn't seem to cooperate nicely. Or maybe I'm just not good enough to master the conditions. I suspect that this is a result of the build up of water moisture in the air as a result of the day's sun on the water. What has surprised me is that all through the morning, different places can still "have good light" at 10 to 11am due to the cliffs, etc.
If I was going to drive US-1 for photography, it would be from the south to the north. The last time I tried that they had just re-opened one of the walkways at Elephant Seal Beach and I got stuck there talking to someone for too long whilst watching the seals :-o The reason for that is there are flatter, more open areas at the southern end that can make the morning twilight and early sunrise work, whereas up around Big Sur, etc, it's not until at least a couple of hours after sunrise that the sun gets over the mountains (well, depending on time of year.)
If you're feeling really dedicated and only have the single day, get up, drive south to San Louis Obispo and over to Moro Bay (arrive just before sunrise), work your way north (to Monterey or Half Moon Bay) and then back south again
That is if the RVs don't drive you insane first :> That'll also give you a feeling for driving on both sides of that road and the different perspective that brings on the winding curves of the coast. If you're feeling tired, find a shady pullout somewhere and have a siesta during the middle of the day O:)