Like you, I dumped my cable and installed Dish over a year ago. I had a Dish dome installed on my RV. However, the Hopper was not compatible with my antenna so I had to add on another receiver, I believe the V722 (?) but not sure. The extra receiver is in my son's room until we leave on a trip. I use he V722 receiver in the RV, but it only works on one TV at a time.
Be sure to check with the antenna paperwork the type of receiver that will be compatible with your antenna. And, check to see if you need two receivers, one for each TV. A call to Dish will probably help too. They are pretty knowledgeable about RV and Dish.
Wayne Lee
Out West Somewhere
2016 Forest River Sunseeker 3050DS Class C | Hummer H3 dinghy