If you have the room I would suggest a VersaTube Carport. I have had one for the past 10 years and it works great. My MH is currently in mine out of the sun, and I store the MH in it during the Winter.
http://www.versatube.com/building-kits/classic-carport#prettyPhotoMine is similar to the picture with the Fifth Wheel, but both sides go down to the ground. I use 10'x12' Silver tarps over the ends to enclose. I would suggest if you erect one, to pour a concrete floor, as mine is gravel and I regret not using concrete.
Also I would build it longer than your current MH, so if you upgrade to a longer RV it will be long enough in the future.