Wow, that’s really hard to read with no line spacing.
Anyway, I think I’m following your question. I don’t know the size of the furnace, but Northern Lites are built in BC, Canada. They don’t build truck campers that won’t heat up or stay cool. They are known for having very good insulation. Assuming you get a basement model, the furnace should keep the tanks from freezing with vents that heat that space.
Personally, I’d buy a Northern Lite if their floorplans work for you. Bigfoot isn’t the same Bigfoot company of years ago. They were out of business for a while. Northern Lite has been in continuous production except for the short period when they had to rebuild due to a fire.
Atwood doesn’t exist anymore since they were bought out. People have good luck with every kind of jack. I don’t think it’s a major consideration for a lighter model camper such as the Northern Lite.