Boat covers and pickup truck box covers are held in place with snaps and they stay on. Maybe there is a grommet type tool that could attach snaps to your fabric. The base of the snaps can be screwed to the frame and ribs of your trailer.
I like using what is available.
I haven't towed anything but often think a small trailer would be handy for long trips.
Hopefully someone with some towing experience will post some info.
Your trips sound exciting!