One of the things I hate when camping is having to find ice every couple of days. A friend of mine turned me on to a cooler insulation insert called the KoolerCap. She told me that my ice would last...
At a garage sale I bought an insulating blanket for a water heater for a quarter. It had never been used. I made a fitted cover for the ice chest and it added several days to the time ice would keep. This was several years ago and I assume they still make them so you could buy a new one. We almost always camp in total shade which makes a big difference.