There is also the consideration of your lifestyle. Some people need to take along more stuff and others are happy with fewer belongings. Do you need a lot of tools and a workbench? Do you have a lot of hobby stuff? What about clothing?
Two people usually cart around more stuff than one person, but I know of couples that live full-time in smaller motorhomes than you are looking at.
So, what you need to do is consider what YOU need to live comfortably and cart around. Are you a minimizer in terms of stuff, or do you like that big coffeemaker and all that kitchen equipment? Will you be hauling around bikes, golf clubs, weaving looms, pets, pet equipment, outdoor cooking grills, grandkids, kayaks, etc.?
Then consider where everyone will sit each day. Will you be comfortable on a rainy day inside? Or even three rainy days in a row?