I ran numerous RG cables from one end of my RV to the other using the air conditioner foam cut ducts in the ceiling. You can pull down the ceiling mounted vents which are about every 6 feet or so and hand feed the cables fairly easy from end to the other.
In my case I had ceiling mounted cabinets on both ends of my 5th wheel trailer and it was easy to run cables up into the ceiling mounted cabinets and gain access to the air condition foam ducts from it. Being foam you can punch you way through fairly easy when you need to get out of the foam cut ducks. Just be sure to seal up any holes that you have after pulling the cables using insulation foam spray.
Obviously all trailers are different but this might be a good place to check to see if it might work easy for you.
The Home entertainment for us was almost half way between the two ends of the trailer and the cabinets there was easy to gain access to the foam cut air conditioner paths.
When ever I penetrated the foam ducts I would use Insulation foam spray to seal up all the egress holes I made. This is important as the air conditioner ducts must be designed to build up known pressures so that the air being put into the air ducts will blow at equal pressures out of the various ceiling air ducts...
Like said this may not work well for your routing requirements but it saved me a bunch of headaches getting to the various places I needed to rout my small RG cables around the trailer.
My RG cables are both used for my Ham Radio items as well as HDTV setups...
This was before the HDMI cables and routers etc all became popular and todays methods may be your better solution for going wireless HDMI routers. I was just looking at some of these at out local WALMART the other day...
Roy Ken