The choices are:

Esky - Inexpensive, convenient, as good as the ice supply, ie. for short periods only.

Three-way fridge - Convenient energy sources - 12v, 240v, gas.  Very heavy 12v power use.  Good for basecamps when run on gas.  Efficiency can reduce with increase in high ambient temperatures.  Needs to be maintained level and stationary for best results.

Eutectic - Cools only 20C to 25C cooler than ambient.  Can also heat.  Reasonable 12v power consumption.

Compressor type - 12v, 24v or 240v.  Can freeze foods, this feature useful when in a group - some can be used to cool, others to freeze, thus maintaining fresh food supply.  Reasonable 12v power consumption.

If a 12v type is selected, it is highly recommended that it is connected to a deep cycle battery as part of a vehicle dual battery system.  Solar panels or a quiet generator may assist in maintenance of power supply at basecamps.  Do not run generators near other campers or at night.