Make sure all your foodstuff is in sealed ziplocks. Or make a dry cooler (search for it). Or better - both.
Go to a local hardware store, get 2 new plastic gas can (they usually have them in blue, supposedly for water, BTW) and a big funnel. Paint flat black.
Pour ice melt into container. Seal container. Set in sun until water is warm. Use for shower and clean-up stuff. While you're using one, the other is warming up. DO NOT let your ice get contaminated with foodstuff (ESPECIALLY Meat Juice). It will stink and rot and negate other use - then, you're trying to evap it off without getting use from it.
IF you keep it fastidiously pristine clean, you can even drink it. I know people who do do that.
WARNING - If you use the gas can thing, DO NOT confuse this black (or blue) gas can for your red Gasoline gas can while fueling your generator (or worse, confuse it wtih your your yellow piss storage gas can when you go to fuel the genny - or take an ice-melt shower...)
I do know someone who used "yellow gas" on his generator - just once.