I was considering to fabricate something out of 1/2" or 3/4" abs from home Depot. Just buy the fittings that I need and dry fit it together to make something that I think will work. We have a Jayco 213 and it also has a narrow opening at into the bunks due to the washroom being built up against them.
2010 Jayco JayFeather 213 EXP
2016 Ford F-150, 4x4, 3.5L ECOBOOST, MaxTow, Supercrew, 6.5FT, 3.55 axle