For drycamping heat, we use two 12V, 115 AH, deep cycle AGM batteries wired in parallel to power the built-in propane furnace. We do not sleep in the cold, so sometimes the propane furnace has to cycle ON/OFF all night at around 65 degrees, just like the furnace in our home does. I don't "believe in" using the little screw-on 1 lb. propane bottles or using flexible propane hoses to fuel propane heaters sitting inside the coach whether we're awake or sleeping. I don't like leaks, especially propane ones that can result from the propane passing through temporary connections or non-rigid connections.
In extreme high temperatures for long periods, instead of moving to another area to camp we keep the coach cool with the larger of our two quiet generators powering the rooftop air conditioner. For short extreme high temperature times, we can keep the entire coach cool by idling the V10 and using the cab A/C.
We're not full-timers, so permanent rooftop solar for day after day long term battery charging is not worth the investment in money, or the holes in our one piece roof, or the panel-cleaning time. If we added solar, it would be via about a 200 watt portable panel so as to provide the flexibility of being able to charge the batteries while camping in the shade. Currently, we top up the batteries every 2-3 days with one of the generators, or by very quietly idling the V10 an hour or two here and there.