As mentioned, DO NOT cover it.....the material from wind sheer will scratch the surface and you will be very unhappy when you realize the damage it will do......find a structure or BUILD on that fits your trailer.......
We just bought ours and got it in April......we are in the same boat.....but we asked and everyone pretty much agrees......no cover......get it some shelter!
If you think a structure is expensive.....cost out the replacement of outer skin panels to replace........you will return thanking everyone later.......