I have hunted in the NWT for caribou, with Arctic Safaris, same general area as you are going to. By the last week you will want warm clothes, gloves and hat. Up there the wind ALWAYS blows, so make sure you have wind blocking clothing. We did a lot of walking, but some did not. So, your footwear is your choice in that area, but again I'd go with something that is waterproof, and breathable. They don't get a lot of rain there, but it could snow in that week. I wouldn't worry about bugs that late, we were there the first week of Sept and saw very few. As far as travelling with guns, your outfitter should be able to supply you with the forms to have filled out ahead of hitting customs. Make sure your ammo is packed (not in carry on) separate from your guns, and if it is a bolt action the bolt is removed and packed separate. Hard cases airline approved cases for on flight, and check with your outfitter on whether or not he wants you to bring soft cases (ours did not). Good luck, I hope this helps a bit. If I can answer any more ?? feel free to PM me.