I want a box to keep some meats for BBQs (sausages etc.) whilst camping but wondered what the best type of cool box is &amp; how long frozen meat would last in a cool box? Or would it be better to store fresh meat rather than frozen? Also want to use it on other occasions for beers etc*. Would need to fit in a small car boot preferably, though I could store it on the back seat when in use.. . *Not that the beers would be for me, as I'd be the designated driver!.