Don't know about Dish, but you can get a splitter for DirecTV. I have a single Coax from the Trav'lr on the roof that goes to a 4-way splitter in the Bedroom. One line to the Bedroom TV, one to the Outside TV, and the Power Pass Thru Port to the Living Room TV which is where the Power Inserter is located and the fourth port is terminated.
This does require a receiver at each location.
Michelle & Ann
2018 Chevy 3500HD Crew Cab High Country DRW, D/A, 2016 RW39MB, Dual ACs, Auto Level, Auto Sat Dish, Stack W/D, King Sleep #, 17.5" Sailuns w/Disc, MORryde IS & Pin, Comfort Ride Hitch, 5.5 Onan, Res Fridge & Induction Cook Top