I used to guide and mountaineer a lot in the rockies prior to the infantry and rock climb, ice climb etc. All of it. I’m still an avid and experienced outdoorsman. This is tragic but very avoidable. Those temperatures aren’t even that cold without a fire if one had the right gear along and that’s one of the biggest rules, always be geared for what you are trying to do. One thing I’ve noticed over the last several years is people want to display things on social media so they do things that aren’t always the most sensible. I’m not saying that’s the case here, but winter in the mountains is no joke even for experienced mountaineers. Ice crampons, axes, etc for starters would be mandatory even if you don’t plan on climbing on ice. It’s being prepared.
Do you ever use a bothy bag?
https://www.amazon.com/dp/B000P9EL06?ref_=ppx_hzod_title_dt_b_fed_asin_title_0_1&th=1