We carry an ice chest anyway. May as well make it a 12-volt ice chest.
… and get to use the entire capacity for food, not half of it for ice and water.
It plugs into the 12-volt outlet in the car and will hold any temperature we set. We can keep it right at freezing if we want. Or it can be powered by the 1,000-watt power source we also carry. That will run it for days between charges. No more wet food. A high-tech ice chest!