jb, if you invest in the best insulated coolers that you can and load up on dry ice, that's probably the best way for you to go. Or at least, block ice from bait shops, which lasts at least 3x-4x longer than cubes.
powered cooler might keep things cooler longer on any given day, but I wouldn't expect it to do a lot of good or to help overnight. I'd try to plan the trip with less need for "cold" anything if possible.
For cold drinks, get a mesh bag. Put the cans or bottles in, lower over the side, and there's usually cold water
some where below 10-20' under a thermocline. You'd be surprised how quickly that can chill the drinks, well enough to keep everyone happy.