Fridge / Freezer
The downside to coolers, eskies, ice-boxes etc is that food an easily become soggy unless stored in air-tight containers. Having a Fridge / Freezer solves all that. A portable camping fridge freezer is also a better option if you're going away for extended times as after a few days at best ice will run out and if there's no ice nearby you'll end up with soggy warm food that needs to be thrown out.
These days with an array of solar panel products on the market along with additional battery power from the car, caravan or battery box you'll easily be able to keep the fridge / freezer powered to keep the beer COLD!