Then there’s the Last Hero. This Northern legend, a favorite of Old Nan’s, tells the story of the titular champion who, in the midst of the Long Night, travels North with his dog (!!!) and a few trusted companions to locate the children of the forest. Over the course of the journey, all the hero’s allies die, even his dog. (Mallory Rubin and I hope, should this legend come full circle, that this refers to the Hound, who can be seen with Jon beyond the Wall in scenes from the second Season 7 trailer, and not Ghost.) But he does find the children, who agree to help humanity beat back the White Walkers.
…Could this be Bran rather than Jon? Aside from the part of it being during the midst of the Long Night, this is a little too on point for him