These coolers come highly recommended. http://yeticoolers.com/
For your food storage question, once made portion them into a zip lock bag and/or aluminum pan and then freeze.
Can you bring in a small generator along to go with what the outfitter provides?
Why not disconnect yourself? My grandfather had an island up in Lake Nippissing with no power / phone. Now, this was 35+ years ago, but it was some of the best times hanging out reading, playing cards, listening to the radio, talking.