....I thought the same thing. We have decided to store our camper at home for the 1st time since buying our camper (2005). We now hove our pick-up unloaded and tonneau connected. Our tonneau cover (for our 8-foot bed, 2500HD Silverado extended cab) rolls up tight and has velcro straps that will allow OUR camper to be loaded with tonneau rolled *tight forward* WITH tonneau rails C-clamped to truck bed rails. All the tonneau cross members and rear span member will store inside the camper, until needed (until needed: IF we decide to unload camper on a trip, we can easily deploy attached tonneau without the need to do a complete tonneau install). However, using both camper and tonneau simultaneously would be, of course, untenable :B
The only caveat: when the tailgate is removed, we would have to un-snap (detach) the rear tonneau cross-member spanning the tailgate.
HOWEVER:
*this works with our particular camper with front bulkhead clearance and camper rail overhang-to-bed-rail clearance, with our particular tonneau cover, on our particular truck ! Your truck/camper/tonneau size brand may differ SIGNIFICANTLY.