I think that's about the size of some cow camps I've summered in. Even with three kids. But we didn't stay inside much and the scenery around us was beyond beautiful.
I'm running into people, retired and most often single, who are living full-time in fifth-wheel campers. Some have been doing it for several years and really like it. Staying in one place at RV parks. My house, at 912 sq. ft., is about small enough and it's basically for sleeping and cooking.
It is not about the space but the amazing things one with vision can do with it.
.Murphy beds have been around for 100 years, Mirrors in strategic places fool the eye as to space , then there is the wallpaper like door covering that fool the eye to believe that the door is half open and another big room on the other side. One big blank wall, build a shadow box with floor to ceiling prints of landscape with light behind it, one can be living in down town Detroit and give the illusion you are living on the sea coast or the middle of the forest.
Paint color can make a room look much bigger or even smaller and more cosy.
We bought a used travel travel trailer with a horrid design, 6' by 28' The bathroom had a 4' bath tub and had we replaced it with a small shower we could have gained big space in the bathroom. Th kitchen set up was compact good size electric referagerator--also ran of propane, plenty of space ---BUT--- across from it they had installed another bench and table that was used as sleeping space for 2 small people. The main area at the front was a U shaped affair with a seating arrangement around a fold down table to expand the whole deal to a king size bed.
Tandem wheels 8 total windows, 2 sky lights. Very nice for a weekend but we should have gutted the whole thing and placed the inside back to front.----
Today I really enjoy checking out the for sale motor homes, boats and 5 wheel rigs for ideas for my home.
I think some of the designers have lived on Submarines as some of the space saving ideas are pure genius.