What is your floor plan?
Luckily, most RV mattresses are just shorter, and most bedroom spaces can accommodate the extra length of a residential mattress with little or no modification. For example, our RV mattress is 74". A residential queen is 80". I could fit the longer mattress in our space, but then I wouldn't be able to walk around it to get to "my" side.
2014 Jay Flight 28 BHBE
2015 RAM 2500 6.4L HEMI, Tradesman 4x4, 3.73
Blue Ox SwayPro (BXW 1503)
Upgraded from an REI internal frame backpack and a Eureka 1/2 dome tent!