In our previous, much smaller rig, we didn't use a trash can.
I put one of these on the side of the kitchen cabinet:
Now granted, those grocery bags aren't very large - but we found they did just fine as long as you make sure they aren't torn.
These back holders work great, don't take any room - and come in two packs - we had one on the outside of the trailer and one inside.
Just remember to take the outside bag down at dark or you may have 'visitors' during the night.
Buddy Ray - Atlanta
Jayco Eagle HT 26.5RLS
Ford F150 Lariat, 3.5L V6 Ecoboost
Max Tow Pkg, 36gal tank
Reese Sidewinder and Reese Titan 16k hitch