[Nirvana58]

With regards to Sansa's letter here are my thoughts. Not really a spoiler but does have some book elements that might or might not been shown in the TV show.

Spoiler!

The obvious answer would think she is sending the letter to Little Finger for help. However, a part of me wants to believe it has something to do with legitimizing Jon. I know in the books Robb sent a letter doing this very thing before he died. Which has been kind of glossed over. I don't believe the TV show even showed this act. Somehow Jon is going to have to receive the Stark name if he is going to bring the North together.