Ches is right, just because the furnace
is old doesn't mean they are no good or not safe. This we discovered after yanking ours out. Have it checked by a professional. Most parts can be replaced. The burner on ours was in horrible condition which was one of the reasons for its removal but you can buy new burners we discovered to late. *&%$# Hindsight!
As for storage, we have a 13' Trillium
and have more than enough storage for all 4 of us. Years ago when first camping with kids we took just about the whole house with us. We look back and wonder how we ever managed to drag that poor tent-trailer down the road. Over the years we have weeded out most of the un-necessary things and if we don't take the canoe (life jackets) or tents we end up with the one back storage bin empty. Funny how we never miss all that stuff we used to think we needed.