I got it figured out. When Jamie runs into LSH he will tell her Arya is still alive and married to Ramsey in Winterfell in an attempt to save his life. LSH thinking one of her kids are alive will march the BWB North with Jamie as a hostage. Potentially hoping to trade him for Arya once they get to Wintefell. When they reach The Neck they meet up with Howland Reed who has just heard that Jon Snow died at the wall. Thinking that theres no point in keeping the secret anymore and that it might ease LSH;s mind a little he will tell her R+L=J. She will regret treating him so badly and want to give her life for his like Beric did. She will march to the wall with the BWB and some Crannogmen. She gives her life to rez Jon. We will learn a lot about the WW from Jon in Ghost and/or Bran and they will link up at some point. Jon will set out North of the Wall with 12 other men, possibly including Jamie Lannister, Thoros of Myr, and Howland Reed. Bran will act as their guide.