I would check your favorite campgrounds and see if they would accommodate your length. Understand they will only have a few sites that length and you will be competing with lots of other campers for those few sites. You probably already know in California you will have to be up early to get reservations on Reserve America for the state campgrounds.
It can be done as we have a 34' 5th wheel and like to go to the state parks. We never show up late on a Friday and always check out the campground for future sites that will accommodate us.