If my whole rig went off a cliff (without me in it) and I had to start my build over with a stock vehicle...the FIRST mod would be the dual battery and the fridge, PERIOD.
The only downside I have found is similar to yours, but different. We used to keep a bag of "clean" ice for mixed drinks. We like to fill a couple nalgene bottles with mixed up margaritas...but you need ice. I like to mix a little seven and seven some nights in lieu of beer...but you need ice. I am working on some ideas with dry ice and a small cooler to be able to bring some clean ice...at least for the first night.
There is nothing better than NO SLOPPY WATER. I freaking LOVE it.
Using the 120V cord and filling the fridge the night before...AWESOME. Can't do that with a cooler.
The extra capacity is HUGE for me (by not using space for ice). We do 5 night trips with no restocking with a family of 5. It used to take two large coolers to pull that off. Now we can fit it all in the fridge.
I would consider a dual battery set up as required. I am planning for supplemental solar power.
I don't know if I will ever go back to coolers...why?
1999 Land Cruiser ::::: ARB front - Warn M8000 - 3rd cup mod - Rear no-bumper? - 295/75/16 BFG AT - Cobra CB - OME lift w/ 863 rear coils - lots still to do!
2000 4Runner: sold...and missed