Agree, pick one quadrant of the country and go nuts, but if you try to make a relatively complete loop you'll not spend much time anywhere. However that could be your gig if you just want to travel. Which is cool too. Depends how adventurous you are.
We never get to take extended vacations, yet, something about work, kids, sports, etc. lol but am taking 3 weeks this summer to go from Seattle back to Wisconsin, and including 3 days in Yellowstone, few days sightseeing and fishing thru ID and MT, 2 days in the black hills and several days in WI, barely have enough time to get back to home base.
Personally I find the Southern half of the country miserably hot in the summer which defeats the purpose of camping and outdoor stuff.
My reccomendation would be upper Midwest out to the PNW/coast, southern BC, cascades, Rockies, maybe hit Moab or something but stay north predominantly.
Or conversely, the NE quadrant, niagra, Appalachians, maybe Canadian maritimes, Atlantic coast.