I agree with all above. I see this all the time when I'm around the campgrounds in my area. And around here Sunday Evening through Friday Morning are Seniors Discount Days. By Friday noon on the family campers are
setting up to bring in the kids for the week end.
You can find tents new for as little as $20 bucks new and in yard sales even cheaper. A tent site would see your Van (even if fixed up as a "rig", a poor mans class B) as your car. But you'd have access to bath houses, perhaps laundry machines etc.
If you are at the Barn, you could get a 2 gallon garden sprayer and splice the hose to a kitchen sink sprinkler to make a "campers shower". The garden sprayer could be painted dull black and set in the sun to warm the water in it for awhile before you hose yourself down in the barn.
Look at how this one is put together
See the kitchen sink sprinkler (for rinsing dishes) spliced to the garden sprayer hose. I'd suggest a 2 gallon size one which you may find at a Harbor Freight store for around $10 bucks. The kitchen Sink Sprinkler
would be scrounged at a plumbing shop or a building material recycle shop for a couple of bucks.
With one of these you could wash up each day. Not like a real shower, but still you can keep clean and feel fresh.