Cold Acclimation – Teach your body (slowly) to not “freak out” when you encounter bitter cold. The book Becoming the Iceman by Wim Hof & Justin Rosales is a great place to start.
Cold Injury – Know about frostbite and hypothermia – the symptoms, prevention, and how to get yourself out of a dangerous situation. This is a short guide that is devoid of too much scientific jargon yet is very informative about hypothermia, frostbite, and other cold injuries, Prevention and Survival by Gordon G. (Gordon Grant) Giesbrecht and James A. Wilkerson
Tire Dragging – I found this to be a great way to build core and leg strength in preparation for pulling a pulk sled. Great article “Lugging Along: The Benefits of Tire Pulling”
ALSO: Here’s a great place to buy high end pulling gear. (I use the waist belt.)
Layers – The key to staying warm isn’t the best clothes; it’s the combo of clothes. Layer 1 = base layer, which wicks sweat off your skin. (I trust merino wool in extreme conditions.) Layer 2 = middle layer is the insulating layer that retains body heat to protect you from the cold (a puff jacket and insulated pants). Layer 3 = outer layer (shell layer) that shields you from wind and rain. This should be something like Gore-Tex.