My setup allows me to bring along a dorm size freezer which sits on my front deck. I also carry a 5-day large chest in the back of the truck always filled with ice. I use a plastic container inside the ice chest so that I can keep cold food in it without getting water soaked. My small inside fridge does not have a freezer at all. We can go a couple of days without re-supplying the ice...
We usually stop at WALMART just before arriving at the camp site and stock up meats and things for a couple of days supply. Almost always have to leave the site everyday for things during the stay anyway...
I haven't looked into it yet but I hear there is a lot of AC/DC marine type freezer/combo now that runs from 12VDC... Would look neat permanent mounted on my trailer deck. These things are probably not on the cheap side.
Roy ken