I was trying to better understand what the question is I guess... Your 18-foot trailer floorplan is basically a one room setup with bed on one end and bunk type on the other end with the TV Console sort of in the center... You should have a cable TV connection on the outside of the trailer.

There isn't much room to add a second TV in this floorplan setup as I can determine.
On the inside there should be an antenna wall jack that looks like this which is the DC source for a roof mounted type crank up BATWING antenna.. Some of the newer trailers are coming out with the JACK antenna on the roof which only rotates. The large socket is a low current (6-8 AMPS or so) 12VDC cigarette light type plug. The F-Connector is to be connected to the TV set. The Black pushbutton applies 12VDC to the roof mounted antenna built-in PREAMP when pressed. A small led light comes on when the the button is pressed..

Does your trailer have the roof mounted "Over The Air" Antenna installed. It should have a crank setup in the trailer ceiliing

The roof mounted OTA Antennas is what you will use to pull in the local towns High Definition Natl Broadcast digital TV signals. We usually pick up 6-36 local town digitla signals just about anywhere we go here on the East side of the US.
This is the Batwing Antenna.

This is the JACK Antenna that only rotates.

Some JACK antennas can be raised up as well just like the BATWING...

Again I got lost in the question you was asking and what you are wanting to do...
Just my thoughts
Roy ken