If you get an electric system, don’t think that everything will be powered from the electrical system. Heat, hot water, and cooking will be better done from gas (i.e. propane). Electrical heating/cooking is rather inefficient. Also many things, such as lighting, can be done outside of an electrical system. Think LucyLights as an example.
I have an RV (class-B - van) and the only thing I normally run from my batteries is my 12-volt fridge. Yep - I use Lucy lights at night because I’m diabetic and my insulin must stay refrigerated. So I don’t run much at night from the batteries. My heater is propane, but does have a fan to circulate the heated air. Also if I have to go to the bath-room at night, I’ll turn on the water pump. Bascally if you don’t need it on, turn it off.
I use my iPad for entertainment when I’m RVing. I don’t charge my cell phone/iPad/etc. at night. That gets done during the day when the sun’s out.
So as was previously said - first understand what things will need electrical power.