Fridge below 40°F, freezer as close to 0° or below as you can get it. I use the Accu-rite remote thermometer
, I also use them on my home fridge too. If you want a cheap check get one of the $10 wired ones from somewhere like WM. That is what I used to use, did the job. However I find the wireless one to be less of a hassle.
Moving air around in the fridge box will help keep it cooler too. I am going to add a computer cooling fan
attached to the fins. Also adding a 12v cooling fan
in the outside compartment isn't a bad idea if will be camping in hot climates. With the absorption style fridges it is all about moving air.