We have 2 large greyhounds which take up a good portion of the interior space but have found the Stowaway works great for our week/10 day trips down the blue ridge parkway. We don't camp out (hotels, motels, holiday inn) so it suits our need for hauling from place to place:

https://www.stowaway2.com/hitch-cargo-carriers

The obvious benefit is that its easily accessible for the Mrs. who's not a big fan of the reach and roof climb. (and in a pinch, you still have the roof space if you happen to come across something big along your travels that you want to take home!)

Locks up and can hold a good amount of stuff. Of course, if you plan on trail blazing/rock climbing, that's certainly not going to work. That departure angle isn't a winner.
It can be taken off by one person (I unbolt the box from the rack and then remove the rack from the hitch) but with 2 peeps you can of course, just slide off the entire setup off the hitch mount.

Every trip we've gone on, someone always compliments us about my "nice ass", "like your junk in the trunk".