We have a 35+ foot two slide gas motorhome. We have been lived in it more than 3 months. Previously we had a 32 foot no slide motorhome and lived in it for 4 months. While I say lived in it, we have always had a stick built home so it's more like vacationed in it. For us, they're doable on a limited basis. If we were full time, I think I'd want larger. That's because there are so many things I'd like to bring that simply will not fit in a smaller motorhome. If your motorhome has the ability to pull an enclosed trailer, that would certainly help. But part of the space would be used to transport your car, if you wanted to have one available.
If you don't have the financial ability to upgrade later, I'd be hesitant to sell your home until you're sure the full time lifestyle works for you. We're on the Coast and prices are high. But I just read that prices in the rest of the country are starting to increase. If you sell now, you would miss any increases that occur making a transition back to a stick built home challenging.
IMHO, the best planned transition to living full time in an RV should include a plan to move back to a more traditional home.