We attended a Hartland open house a couple weeks ago. Some of the new 5th wheel units had residential fridges in them. They had two 12 volt batteries feeding a 1000 watt pure sine wave inverter. This is all they had power on 14 and 20 cu ft fridges. Most of the smaller fridges draw 300 watts to cool. But when cool do not run all the time. Not sure about starting though.
I am going to run with only 2 batteries until I find out I need more. My motorhome has a auto start on the generator. If the batteries get low. Generator will start and recharge batteries.
The real battery hog is our furnace. 2 batteries will not run furnace overnight in 30° weather.