Having worked LE in North Dakota for the last 17 years I have gained some insight to working outside in -40 weather. Our first IDPA match of the season is the 2nd Saturday of February which is usually the coldest month of the year here.
I use synthetic lube on my guns. For weapon manipulation in extreme cold gloves are a necessity, without them your hands will instantly freeze to any metal and exposed skin starts to freeze in seconds exposed to the air so frostbite is always a concern.
For short duration exposure to the extreme cold I like the Hatch Kevlar frisk gloves for shooting.
My usual Patrol Gloves are thin leather insulated. As has been mentioned dress in layers. It is very comical and humbling to draw from under car-hart bibs, which is one of the many reasons for a J Frame in an outer pocket.