Clam Quick-Set Shelters
The small 6x6 Clam screen room is what I have, it works well for me and the dog.
You cannot very well use them over top of a trailer. Some have a floor. Some have flaps that go over side walls to shed rain. Some do not. In the Northwest, I need the flaps and wind panels. I purchased enough wind panels to put one in front where the zipper is, then use a propane heater in cold weather.
If it rains, one has to put it away wet, and dry it out when one gets back home. I wish they made a waterproof bag because I've gotten mine soaking wet by having it in the roof basket.
The 6x6 is only about 53 inches long when in the bag (others are longer), so I can get it in the backseat floor if needed. I can put it up and down by myself which is necessary, as the dog only supervises. There is room for his bed, my chair, the heater, and the portable toilet in there, and even a small table.
I think I would rather use the Clam in wind because it seems like it is easier to tie down than the awning--and less expensive if it needs to get replaced. I don't know about a big wind like at the coast, I might chicken out and take it down.
It does not give me anything to have over the galley, but does work pretty well if close to the galley.