Reading this thread reminded me of a tip I tried with mixed results
We liked to tent camp and with our 4 kids along always getting into the ice chest containg drinks the ice was always an issue. I read on a website that you could extend the "life" of the ice by adding rock salt..... I agreed thinking this is how you freeze homemade icecream

so on our next outing I loaded the icechest with probably 3 cases of sodas and bottled water that were room temp. I added a layer of ice followed by a LIGHT layer of salt then more ice and more salt. Didn't think I used that much because this was a new idea so I went conservative, or so I thought. We drove to Big Sur, gotta love Calif. coastline, set-up camp and settled in. Later that evening my son went to get a soda and wondered why someone put their empty can in the chest

He grabbed another one, when he tried to open it it was froze to a slushy-like state.....we all thought WOW this really works

Until the next day when everything was froze SOLID, there were even cans that burst, ripped the can right down the side. So needless to say, ice was not an issue that trip, but there were a couple of drinks runs that had to be made. So I guess in moderation, say fill chest with drinks, then ice, then a little salt on top should suffice. I haven't tried it again because SHE won't let me

LOL So folks, there's my 2 cents, enjoy.
