We do quite a bit of boondocking in the desert. Our former coach, 04 Southwind 36 had two 6 volt batteries for the house. They worked fine through the night supporting a furnace at 68 deg and a CPAP machine (no humidifier).
Our program began as the sun began to set reducing lighting to only task lighting, reading lights and kitchen work lights. No TV (seldom watch anyhow so this is no sacrifice). Bedtime, the only items operating were the furnace and the CPAP which is powered directly by 12 V no inverter needed. At the point this stopped working satisfactorily I decided that 7 years on well maintained batteries was a good run and I replaced them with identical Trojan 105s. By then I had added solar. In the morning I would start the generator to make coffee and toast and start the battery recharge. Generally two hours. Then two hours during happy hour and dinner prep and maybe an hour leading up to quiet hour.
The current coach, with twice the battery pack requires aome more attention to detail. Had a 12 v outlet set in by the head of the bed for the CPAP once I learned that even 4 batteries would not support the furnace and Inverter and CPAP. Many more phantom draws on this wonderful coach. Need to turn off the inverter when not needed while boondocking, otherwise it is always on. Need to be sure there are no hidden lights left on even though all are LED. Added 340 watts of photovoltaic to the roof and power management with metering so I know the status of the batteries. Generally run the gen in the am for coffee and toast and in the pm for dinner prep. Don't usually bother with a late evening topoff anymore.
Short answer with some rather simple attention to power use and adequate charging there is no reason you can't enjoy boondocking even in the chill on two well maintained deep discharge batteries.
