I came across this documentary a few months ago and remembered it today when a friend mentioned the Chadar Trek. You can watch the entire video but I recommend starting from 7:18. That’s when the bit about Chadar begins.
David Attenborough has set a high bar for nature documentaries. Anything less reveals its flaws right away. The above video uses some gimmicks for cheap thrills but check it out regardless. There aren’t very many videos of the Chadar.
Several Himalayan adventure companies organize the Chadar trek of the Zanskar valley in the Himalayan winter. If you have the time, money and motivation, go for it I say!