I winter camp a decent amount. My coldest was -7 overnight. I wasn’t the sharpest tool in the shed because I only had a +15 degree sleeping bag. Very uncomfortable night.
But, my cell phone and camera batteries all died quickly. Several car batteries also needed a boost in the morning.
The guy on the right sure seems to carry a lot of electronics. I wonder how they keep them warm and charged.
It looks like their jackets might be Aerogel. IIRC, 1 mm thickness Aerogel is the same insulation as 30mm of down.
Redundant GPS and sat phones. I-phone to keep his sponsers and followers updated (promo/ $$). If it was me - I would have duplicate paper maps and at least three standard compasses of various types.
I wonder if there is a place where you can store the stuff at -10 degrees for awhile to test it on your own that it will still work?
By the way, if -15 is balmy, how does global warming melt the ice and snow down there? (Well - bad example, as in Antarctica the levels are actually increasing.)
Many long years ago my Explorer Scout post went on an early spring camping trip and visited the Henry Ford museum in Dearborn, MI. One night was so cold (I know, vs Antarctica a totally vile sound accompanied by middle finger salute) that the post’s adult advisor attached a string to his member so he could find “himself” underneath all his heavy clothes.