Winnebago's ERA 70C has a rear bath somewhat larger than the one Forest River put in one model of the MB Cruiser. But this floorplan, which looks like it was designed for single full-time living, has no permanent bed, and the foldout sofa bed needs a slideout to be opened for you to unfold the sofa. Specs don't give the size of the refrigerator, but since it is a two-door model, probably at least 6 cu ft.
Sportsmobile, which custom-builds on Ford, Chevy, Sprinter and Ram Promaster vans of all sizes, can build a rear bath in some of the extended vans, but maybe not always a dry bath, because not all long vans have a long rear overhang. Design your own, it's fun. Then they'll tell you whether or not they can do it, and help you work out a compromise they can build.
Tom Test
Itasca Spirit 29B