I have a Hopper/Joey setup in my 5th wheel. But I cheated. When I ordered my upgrade at home, I asked for a 2 Hopper, 4 Joey system. When the installer showed up, I told him I wanted 1 Hopper, 3 Joeys in the house and the other Hopper and Joey in my 5th wheel. He wasn't sure, but said he would do it. He said Dish rules prohibit him from going up on the roof of the RV (I have a Winegard Travler). I convinced him that by researching through Satellite Guys that I knew what had to be done, so he said ok. So, I sorta cheated to get my system set up. I have not been beyond my local area yet, so can't say what does or doesn't work as far at PTAT. I have been 250 miles from home and it still worked, but I assume I was still in my home zone.
That probably doesn't help your situation, but that's what I did. I have determined that if you dry camp a lot, the Hopper/Joey is not the best setup, as the Hopper obviously has to be powered up for the Joey to work, so that sucks a bit of battery/inverter power. It definitely requires more power than, say, a 211K. Just an FYI.
As for as special wiring, my 5er was already wired for 2 receivers, so it was pretty straight forward. The Travler has the exact same 1000.2 dish as all the others.