I am amazed to find that Nat'l Geo has allowed the full segments, 45
minutes each, to be publicly available on YouTube. Here are the links
for the three segments. (There's an ad for a new kind of insulated
jacket leading each episode for maybe 30 seconds.) So you can watch any
of these anytime, at least as long as they keep these available, which
probably depends on the sponsor. I don't think there's any way to record
the video off YouTube.