I looked up the weather for 50K years ago and it was generally a touch cooler than today, but close.
Why would people live in Tibet when they could live elsewhere? somewhere warmer...
https://www.esd.ornl.gov/projects/qen/nerc130k.html
By around 60,000-55,000 years ago, conditions around the world had become warmer, though still generally colder than today. The ice melted back partially, and there followed a long ‘middling’ phase in which the climate oscillated between warmer and colder conditions, often in sudden jumps. During some parts of this phase, conditions in the tropics may have been moister than they are at present, and at other times they were drier. Generally, the mid-latitude zones seem to have been drier than present, with cold steppe and wooded steppe instead of forests.
Maybe they had to leave where they'd been living because of incursions, or, maybe they were once so numerous they just expanded into every nook and cranny. Doesn't mean they were numerous in Tibet. :^) They probably were good at making warm clothing. Or, maybe this was a captive of whomever else lived there at the time, raided out of his or her home.