Hi jeremyhart72,
The basic idea is sound. You need a dish that supports multiple outputs, or a splitter that will work with the dish. You need receivers that are compatible with the dish. If you have multiple satellite coax lines in your RW, you can feed dish output to each, with receivers attached to the other end of the coax.
Satellite signals will not work on the cable/antenna coax wiring in your rig - the satellite frequencies won't pass through the signal booster or splitters used on those lines.
Many Heartland trailers have the outside satellite connections in the UDC (above the water connections). If your rig is pre-wired for a rooftop unit, there may be 4 connectors. 2 go to the rooftop pre-wiring. The other 2 typically go to the living room and bedroom. If you install a rooftop dish, you would use jumpers to connect the rooftop wires to the living room/bedroom connectors in the UDC. If you use a tripod mounted dish, you would just connect the dish to the living room/bedroom connectors in the UDC.
Some rigs have basement TV and exterior wall TV coax lines, but I don't think any of those are for satellite connections. If you want to place a receiver at one of those locations, you'd need to run new coax, or skip the receiver at that location and replicate the output of one of the other receivers to that location. Same if there's a single coax connection for a garage TV. It's probably cable/antenna, not satellite.
There are other important considerations. Dish or Directv is key. High def vs Standard Def is key. Auto-satellite aiming vs manual setup is key. Once you make those choices, you can start looking at dish and receiver choices.