Chuckster gave you the logical answer. He is an RV tech and does these things daily.
He referenced loose ducting because many, if not most, new trailers have problems with the way the ducts are sealed, separated and routed resulting in less than optimum airflow.
On the other hand, if money is no object, you will need to peel the roof off the front of the trailer, cut a 14x14 hole, reinforce the roof around the AC and add supports for it, run romex from the AC panel to the new AC location, upgrade the electrical panel from 30A to 50A then purchase a new 50A service cable. You could forego the romex, new panel and 50A cable and just run an extension cord to run it, but, if you're going to do it might as well do it up right. Anyway, you can see it will be a chore to do it right.
I'm not sure if anyone has actually done what you suggest but I'm sure they will chime in if they have. I know some have added 2nd ACs with 30A service and ran an extension cord or some other method to power it. Some with 50A service just drop a new one in the hole and wire it up - they are usually pre-wired and supports already installed.
I'm with you though, if you're from Baton Rouge I don't see any way you can operate with one AC. Don't know what size you have but if it's just 13.5 you could look at upgrading to a 15k. I'm also very surprised that there is no vent in the bedroom. If it were me I think I'd be looking at a 2017 model with an AC in the bedroom
. Good luck.