Most high-wall popups have a shower/bathroom and toilet with holding tank. They are not seperate shower/toilet bathrooms but more of a wet-bath. We had a Fleetwood high wall pop up years ago because DW and DD didn't like the campground facilities either. The walls are very easy to set up/take down. The holding tanks aren't big and dictate a 'navy shower'. Take a look at the Rockwood High Wall series floorplans.
I had a Fleetwood Niagara ounce. It had the wet shower toilet combo. Worked great for us. The only problem was the capacity of the holding tanks. Black was 10 gallons and the grey was 20 gallons. If we stayed anywhere for more than a weekend we used a portable tank that hooked onto the trailer ball and we hauled it to the dump station behind the truck. It was just a little chore that we did. not really a problem.
Retired Fire Dept Battalion Chief
2016 Ever-Lite 232RBS
2012 F150 FX4 W/Max tow & Ecoboost
have you looked into hybrids? The best of both worlds. We camped in a pup for 25 yeard, just switched to a hybrid this year. A real bathroom! with the camping feeling of tent beds. Love, love, love it!
2014 Rockwood Roo 23IKSS
2012 Dodge Ram 1500 Hemi 4X4
Me, Hubby and Luna the Lab
I had a jayco pup in the past with bath and grey holding tank. I was surprised that the grey tank only held the water from the shower and not the sink. The black tank was a thetford case that you pulled out, was a little messy.
2013 Tracer 240 AIR
2014 Silverado 1500