Try to stick to his normal schedule as much as you can. If he tends to take his nap at the same time every day, plan to be back at the resort at that time. Even if he doesn't sleep as long, the down time will be good. And try not to let him get
too far off his bed time. I found bringing pajamas to the parks in the evenings was great, I would change DD and put her in pj's before heading back to the resort. That way if she conked out in the car/on the bus we could carry her to the room and just put her right down.
Definitely bring his favorite snacks, and a couple of new ones too. New snacks are great distractions while waiting in line, at restaurants, etc. I also go to the dollar store and pick up some new coloring books and little toys like cars, etc. Having "Mommy's bag of tricks" at a restaurant can save your meal.
Made-ahead diaper change and feeding-time kits were a life saver! For diaper changes, take a gallon size ziplock and put in: diaper, a few wipes (I put these in a sandwich bag), and a disposable change pad. Then when it's time for a diaper change you can grab a kit, hit the restroom, put dirty diaper, wipes, and pad into the gallon ziplock and dispose. Much faster & easier than dragging the whole diaper bag in. For meals I would put a disposable bib, couple of individually wrapped Wet Ones, and disposable place mat in a quart size ziplock. Then we'd be set for the meal and again, all the dirty stuff gets zipped in the bag.
Bring your own stroller from home. Yes, it can be a pain in airports and on the buses, but your little one will be far more comfortable and having the recline is great when he zonks out while you're walking around the parks.
Child Swap is nice, but to be honest we just used Fast Pass and took shifts with DD. It just easier sometimes.
Congrats on winning a trip, how exciting is that?!?!
Have a great time!!!