OK. If your more after Caribou, go 1 week later and have the pilot fly around until you find them and land at the closest Lake available. If you set on those dates, do the same, but the chances of seeing them is less, IMO.
If your more set on Deer, go to Grants Lagoon and hunt high. Lots of nice bucks up there. And while your up high scout for Caribou, they migrate and travel a lot. Another good spot is having the Pilot land at the Weather Station lake, good buck hunting all over there. If you go 3rd-4th week of September, you'll see Caribou in the area.
I recommend Andrews Air, best flyers over there and will bend over backwards to find the critters before you land, as opposed to others........