We have good success with deep cycle batteries for our camper and the fifth wheel.
With the two 6 volt 'golf cart' deep cycle batteries in the fifth wheel, we can sit for up to 5 days without charging the batteries, same that we did with the 12 volt deep cycle marine battery we had before the two 6 volts. The 12 volt marine battery was heavy and larger than a regular 12 volt battery, but it was durable.
With the camper, we've sat numerous days without charging its single 12 volt battery.
Maybe we're just frugal with electricity ... and maybe our cooler temps in Yukon mean the fridge isn't cycling on and off as much.