If for some reason you find you have to use single use water bottles, or someone else does and you can get your hands on them, grab 6-12.    Re-fill them just over 3/4 and stick them in your freezer and Voila!   I use these in my cooler instead of bags of ice.  They last longer, they don't leak water into everything in the cooler, and in a pinch you have ice cold water to drink as they thaw. 

What other car camping hacks do you have for food prep and carry?