Gracemely,
Sounds like an awesome trip you've got planned! One thing that I've heard from folks that have lived/worked in sub-zero climates - things that you take for granted normally don't work as well in such cold environments; just as "Duncan71" indicated about the belts.
Here are a couple of suggestions I'd consider:
-- I think I'd pop the drain plug on each diff, the trans, and the X-case to drain out any water that may be laying on the bottom - then top them all off with the correct fluid. This will remove any sediment/water and ensure you that they're up to snuff on fluid levels.
-- I'd also make do a quick inspection of all suspension joints to make sure they're in good condition & I'd grease them just prior to departure.
-- If you haven't in the past 6 months, I'd pull each wheel for a quick inspection of the brakes. No need for a leaky wheel cylinder to get worse out in the middle of AK! I'd also do a quick 4-wheel brake fluid bleed to remove any moisture at the wheel cylinders..... Same goes for purging/bleeding your hydraulic clutch system.
-- If your battery and alternator more than 2yrs old, I'd simply replace them now with premium parts. With as much as you'll likely be using your lights, wipers, heater blower fan, you don't want tired units to give up the ghost with such a work out........
-- I'd do a Rain-X treatment of all my windows inside and out. It will reduce the formation of fog inside and make outside window ice/frost scrapping a tad easier. Replace your wiper blades with premium units and pack a spare wiper blade/arm.
-- I'd throw in a 1st-Aid kit. When it comes to packing drinking water, I wouldn't just pack clear water - I'd pack a plastic jug of Gatorade. It won't freeze up as quickly as clear water would. Nevertheless, make sure it has an inch or so air gap for freeze expansion or it may split the jug and make a mess.
-- I'd have a small tool kit and include a few extra lug nuts, a 10-12ft spool of wire, duct tape, electrical tape, starting fluid, brake fluid, spare tire valve stem guts and removal tool, & a can of radiator stop leak.
-- Check your tire air pressure more often, you can develop rim & stem leaks simply from the cold. Just being colder will also drop your pressure without a having a leak. Include checking the pressure in your spare tire(s).....
-- Pack a 20ft jerk strap and a small shovel..... for obvious reasons.
-- If you don't have one, get a cell phone with a GPS tracker. Talk to your phone service provider and ask if you will have service along the route you plan to take.
Good Luck, have fun, and take some pics if possible!
J-Quad :cheers2: