Older engel 45 family of 4 we can manage 4 days out easy
The 65 would be nice at times depending on what you eat and want for luxury fun foods like a gallon of ice cream to break out 3rd night and have ice cream
When we had our trailer we had the 65 in the trailer and the 45 in the rig we used the 45 as the freezer and 65 as fridge which was luxurious on a two week trip
With just the 45 we also have a cooler with ice still for all the kids juice packs and other things we want to keep cold but dont want to open up our fridge for
kids like to look for a while and decide
For the ice freeze water quart jugs so can then drink or use the water for cooking if we need
Our fridge is set close to freeze so our frozen stuff stays frozen or just starts to thaw around 4 days yet non frozen items wont freeze up