Been there many times. Moosonee is not part of the reserve, that's Moose Factory.
Did a painful exercise with a hundred or so noob's, two up, towing 500 lbs of gear from Cochrane to Moosonee. That took two days of freezing frigery.
Another exercise we loaded trucks, trailers, sleds and all the food, tents, gear etc for half a battalion on the train. The train ride is pretty cool. Most flew in, I got to fly out back to Orillia.
Done Cochrane to the Canyon in around 3 hours, from there to Moosonee shouldn't be more than a few more hours on fast sleds.
Cochrane to Moosonee would be an easy day for experienced riders.
I can't see them not putting in the ice road. It's a life line for supplies and travel....but I've been wrong before...
The peeps that live North of the Moose don't need licences, insurance etc...until they get to town. Vehicles get parked at that line, and they get a ride into town lol