If your going out of Moosonee you are either going in by train from Cochrane or flying in from Timmins. The Argo is a great idea but it may be pricy getting it there.
The area is low, and wet for the most part. High rubber felt lined boots with spare liners is the only boot of choice, this is no time for the gore tex chit. On your person have a map of the area 1:50 scale, compass, two bic lighters, a Fox 40 whistle, a good wad of toilet paper in a zip lock bag, and yes wet wipes in another zip bag. Take good care of your bottom end and it will take good care of you. 20 rds. of ammo, 10 in a rack in the L coat pocket + one 5 pac in the R + 5 in the gun. Two knives one a good hunting only used if you have meat on the ground. And a second knife for general use. About 10- 15 feet of small dia. nylon cord (parachute type cord). Roll of orange flagging tape. Chocolate bar to snack on. Your far enough north there I just drink the local river/lake/creek water. Yeh I know you could catch 10 different diseases from the water. But I haven't in the last 40 some years. Besides you going to die eventually anyways it might as well be from bad water while hunting. Leave all the electronic crap at home, eg: cell phones, radios, GPS, there just weight in your pocket usually with dead batteries. A GPS can be usefull "IF" you know how to use it. Most of that stuff is used by new generation sissies who never took the time to learn how to use a map and compass.
All the above will fit in your pockets, won't weigh you down and will be sufficient to get the job done. Learn how to call using your hands, saves dragging a moose call around. Most guys carry way to much chit around with them in the bush. You will be with an outfitter so he will be babysitting you anyways. Have good time.