I've never been inside a motorohome but have been working some ideas for another RV'er wanting to remove his BEDROOM area and make a large working RADIO CONSOLE/OFFICE area out of the room. He only plans on using his motorohome setup for a HAM RADIO/EOC console for Ham Radio/RACES/SKYWARN operations.
You didn't mention the model of your motorhome but if is like this 26DS model under the BED and WARD shown here is the large storage area under your bedroom area. Perhaps a small door could be added to what you have under the bed or maybe an access drop hole in the floor of the WARD cabinet. You could just place a laundry basket under the hole area. This chute idea is very popular with fifth wheels. The area under the shower side is pretty much taken up by the generator...
Provide some model number info so we can look it up on-line for you to get some ideas.