We always boondock. Never plug in, never bring the generator. A 100 watt solar panel and charge controller keep the batteries over 80% charge all the time in summer here in sunny northern Alberta. I have the house batteries and engine battery connected so It is also kept charged. We have all LED lights, no TV and the microwave oven serves as a bread box.
We just had a week at 20 below zero C and a foot of snow. The snow on the solar panel put it out of production, and the engine parasytic current draw discharged the engine battery well below 50%. I’ve got the smart charger on it now and am hoping it isn’t damaged too badly.