We drove from nj to fl (17 hours) with our irish twins 2x, at 10 & 22 months and 1.5 and 2.5 and our best bet was to get up at 2am let the kids sleep, stop for breakfast do a little more driving then stop at a restaurant with a play area for a break.
it is manageable with no overnights, but decide that if it becomes unbearable you will stop at a reasonably priced hotel. we once stopped for 3 hours for $50 just to get out change the kids, etc.
as far as the resort is concerned we have always been able to check-in early. and if we had to wait we relax and the pool or playground.