I'd say so yes.
We've been camping for a few years now and although we started out with just a cool box and ice packs regularly re-frozen from the main campsite freezer, we now allow ourselves the luxury of going on the electric line and just keeping everything in a mini fridge.
Don't buy a cheap one though.. unless it is on sale.. or you will need to switch it off every night when you go to sleep. Most have an Eco mode that once it is cold you switch over to and you'll hardly hear it.
It's so handy to just keep milk, butter and basics cold.
Enjoy your camping trip, we got everything wrong on our first holiday but still had a wonderful time. I think a lot of it is down to where you are camping and whether the kids have other kids to play with. Oh... and the weather!!!