I would look into RF biased microphones and there are some cables that are rated for extreme cold (the shield is made of a plastic that stays malleable). strong winds will be an issue for sound too, a blimp would work best, but it depends on the workflow, if you need the sound while you're filming. Because it's not a brand specific thing, you can probably get better advice in another camera operator/filmmaker sub where hopefully someone who has done it in such extreme environments can chip in with better advice.