Also, Howland Reed may be the only living soul who knows Jon Snow's true lineage.

I'm hoping the letter Sansa was drafting is meant for Howland Reed at Greywater Watch. Between the crannogman's guerilla-style battle tactics, and Sansa & Jon's intimate knowledge of Winterfell, they stand a fighting chance against the asshat formerly known as the Bastard of Bolton.

Weiner's writing is airtight. Even lines which seem like throwaways have significance.