I just increased the font size and was able to use the cursor to help me read your post. I will keep my comments brief but feel free to pm me if you like.
Your choice of Northern lite is perfect in my view. We have driven the Dempster in late fall, ran into a blizzard etc. with our Arctic fox see my sig. That is too much camper for that type of off roading. Even pulling off the road into a gentle swale you go dead slow and it still feels top heavy and adds strain to the camper mounts.
In cold temps you want to stay away from a slide even in a four season camper. By the way we absolutely love our Arctic Fox and wouldn't change it for the world.
I would suggest a one ton short box extra cab with a suitable Northern lite, the lighter the better. And a gas job for sure in those temperatures as you will keep it idling for much of the time.
You will need a good on board gas powered gennie (propane is too loud ask how we know) to keep batteries up as there is very little daylight north of Dawson for the dark months. Research additional heat source that does not require forced air such as direct vent propane heaters.
Figure out how to carry two or three spares and keep jacks etc. where you can get at them easily. Same goes for spare gas you can never depend on making it to the next lodge as the highway can close at any time and stay closed for a week from the wind. So always enough gas to turn around and get you back to Dawson etc. Maintenance shops will not sell you gas.
One last thought is a way to keep some heat on your propane tanks even a trouble light will work with incandescent 60 watt bulb or better yet low wattage battery warmer.
Oh and complete arctic package for the truck, 60 below coolant, battery blanket, dual batteries, oil pan heater, block heater, and interior car warmer for starters.
