Some reading about available amp hours in your battery and the amp hour draw of a even modest electric heater (plus the loss for an inverter) should be your near future. Three days of conservative water use shouldnโt force dumping unless you taking an army. Many of us are dry campers/boondockers. You can have a great time even if not in an RV hotel. Last, Iโm a solar guy but a small backup generator comes with me on every trip. Havenโt needed it in the last 6 months but it comes along.
Winnebago 2101DS TT & 2022 Chevy Silverado 1500 LTZ Z71, WindyNation 300 watt solar-Lossigy 200 AH Lithium battery. Prefer boondocking, USFS, COE, BLM, NPS, TVA, state camps. Bicyclist. 14 yr. Army -11B40 then 11A - (MOS 1542 & 1560) IOBC & IOAC grad