Mattt, I'm going to do you a huge favor, I'm going to take everyone out in the boat snorkeling for you! You stay home and tend the fire! LOL If you're planning to pull at 3 a.m. and then pull at 7 or 8 a.m., as the others have said, if you wrap good and cooler I think you'll be ok. Some folks have written they've gotten upwards of 6 hours in the cooler!
My last butt, I pulled after being double wrapped in foil, added one more tight wrap of foil, then tightly wrapped in 2 towels, put in the cooler and filled with blankets....at 4 hours I pulled from the cooler (older cooler) and the internal temp was still 180*! Even if you could start an hour or so later in the evening, it'll give you less time in the cooler. Though you may get a little less rest for the boat ride, but I have that covered for you! Good luck and just wrap everything tightly and make sure you fill the cooler completely with blankets, towels etc.