When our power goes out at home, sometimes for days
at a time, I now buy dry ice for my fridge. It lasts for a couple of days. I
have seen people use this in their coolers when camping. It can freeze some
things you don't want frozen, but maybe you could keep some water bottles
between the dry ice & your food. I haven't tried it myself for coolers
and I also had lots of ice water on the 2nd day, but fortunately no
perishables.
