We take winter trips to southern destinations from our Oakville location and have never stayed in a motel even though most campgrounds in the north or near north are closed. We do stay overnight at Flying J's, Walmarts, etc. and have never had any problem with insufficient energy at night even with our cheap and puny 95 A-h type 24 marine/RV flooded-cell house battery from Costco. All our lights have been upgraded to LED types, and we'll watch a minimum of TV to save the energy for the furnace blower and water pump. For safety issues, I would never contemplate idling the engine for such long periods even if the alternator could supply enough energy to keep the house battery fully charged (which I doubt it would).