I forgot to mention the SF traffic. If you're not used to driving up there, it would be better to park the car somewhere and use local transporation. Less stress, and will probably save you some money and time that would've been wasted looking for parking.

As far as taking PCH all the way up, I think it might be better to jump back and forth between 101 and 1, the 1 is very twisty and slow, and once you've seen 4 hours of ocean at 20 mph, the view pretty much stays the same. Especially at night when there's nothing to see, I would definitely recommend travelling on a major highway