I think if you are using the tailgater, you will need two receivers in your trailer, one for each room you plan to watch tv. I use Directv and use two receivers if I want to watch in two rooms, at least watch different programming at the same time. I'm more familiar with the Direct tv since I have no experience with dish.
Trial and error is a good teacher.
2010 Jayco Quest G2(SOLD)
2014 Jayco Eagle 33.5RETS
2007 Ram 2500 5.9L Cummins(SOLD)
2015 Ram 2500 6.7L Cummins 4WD