I will also vote for 2 batteries and solar.
I have two 110 Ah batteries, and 2 100w solar panels. With this, I have done 3 nights with day temps in the 30s, and overnights in the low-20s. Furnace set for 65° in the evening (we aren't around during the day), and 45° at night.
I have all LED bulbs throughout, and don't have a TV. Use water heater (gas), water pump, furnace, and lights as we want. Always have plenty of battery power.
I love my solar, as we have been dry camping and used heat overnight for a week (overnight low of 30°, and wife needed heated during the day, as temps only went to 50°, for each of two weeks), and have not run low on power.
I am a solar advocate, as it works great for me.