There is usually an input near the Bedroom TV for a separate SAT box. Use that connection for the DVD player. If you need to you can run your own IR cable setup.
You may be able to mount the DVD on the bracket behind the TV and install an IR devise to reach the front.
If your 4X4 HDMI box is not using all of the inputs install the DVD in the front of coach and install an IR over HDMI devise in the bedroom so you can control it if they are using HDMI cable thru out.
There are ways it just takes a bit of asking the right question and or Asking Google