One of the most pointless, dull storylines is that of Brienne and Pod, but nobody earns that much screen time in Thrones unless they have a major role to play. There have been hints of support for Sansa, coming in the form of "the North remembers" and instructions to light a candle in the tower if she's in trouble. Surely Ramsay and the equally messed-up Myranda are both candle-burning situations. Brienne needs a purpose, and closure on her oath that has rumbled on for too long. This is her way to earn favour, and with her nemesis Stannis also en-route to Winterfell, a clash between the pair is a very real possibility.