Oh, it was definitely risky, no doubt. It just seemed like they established the huge mound of snow more to show the means of their escape than to have people expect it to be a deadly proposition. Plus, they've both lived in the North all their lives or nearly as long, so they probably know more about snow and how…

It didn't thaw, they showed it right before they jumped. Are people really not paying that much attention to things like this? It was right there.

Sansa and Threek didn't jump to their deaths, do people really think that? They established the gigantic snowbank right under them, and it's been snowing for weeks. Come on.