How important is the UW shot to you? If you're not very picky, what you can do is keep the 10-22 + 40D setup, and dedicate that combo to landscape shots you're taking. (I don't think there's anything wrong with the 10-22, so why spend the extra cash for the UW L lenses?).
If you really want the extra stops and cannot settle for less than the picture quality provided by the 5D3, you can sell the 10-22 and pick up a UW for the full frame. In this case, you'll have to bring your FF body when you want to take those wide landscape shots, leaving your crop body solely for the tele-shots.
If you want keep 10-22 for crop body but also want to use the 5D3 for landscape shot (and have cash to invest), buy the 14mm or TS-E lenses for the FF body. This way, your crop body (with zoom lens) and FF body (with UW primes) will have different roles to play.