We went from the Bay Area to Seattle not so long ago. We had books on tape and the favorite with the two year olds was Caps For Sale. They also loved the Cinderella tape. We took three days to drive up. We drove about 5 hours per day.Spending two nights in hotels with pools. The ride back was a straight 12 hour drive between my husband and I. All three kids slept the entire twelve hours. When we reached home the parents took turns napping the day away.
My son spent the entire second day, on the way up, playing with a small motorcycle while sitting in his car seat. We stopped for lunch and some playground time about every two to three hours on the way up. I had my stash of puppets, music, stickers, lolipops, snacks, tapes, music, crayons, markers, books, ect. in the front seat within easy reach. I was exhausted and car sick for the ride up but the kids were happy!!
Hope your trip is as easy as ours and enjoy the vacation time.