Should work fine, Scott. Same scenario I had before I swapped out the old CRT TV for the new LED 37" up front. Finally got tired of too many remotes and too many devices. I bought the Jack before making the swap, and had it wired just as you've described...cable coming down from antenna on roof into the Jack powerpack, out of the powerpack into my signal/tv switchbox.
Good luck, and let us know. Btw...don't know what kind of "cover" you're under, but you may not even need to move the coach to test it.
Jim