With a large older dog we need to give her as much floor space as possible, even if it means we loose the dinette (which we will reinstall once she passes on).
We're torn between a TC and extended cargo van conversion
We had two larger dogs in our old truck camper and it worked out.Let them pick out there spot then if it works,you just have to learn to maneuver around them.We got one of them to get up on the cushions behind the dinette and the other larger one had the corner area for his spot..
Your options for a dog and room in a truck camper are greater than with a conversion van.