I faced the same issue with my 2011 Georgetown 327DS and installed an A-B switch on the coax from the rear of the rv. The rear coax goes to the common port, A goes to the switchbox and B goes to the satellite box. When we're in a park with cable, the signal from the rear jack goes to the switchbox wnd when we're staying somewhere an using the carry out satellite dish, the rear jack cable goes to the power injector then on to the satellite receiver.
The A-B switch avoids having to change cables in the overhead compartment and allows using the single input cable from the rear of the rv for either purpose.
Before I purchased the wireless HDMI equipment, I took the video output from the satellite box, ran it through an RF modulator, then through the switchbox's AUX input to feed a signal to the televisions.