Was talking about this with a coworker. What if he is cast as Howland Reed?Deadwood's Ian McShane has been cast in an as yet unknown role for next season. Speculation is that he'll play either Balon Greyjoy's brother Euron or Samwell Tarly's father Randyll
We think they may be doing a flashback with Ned/Athur Dayne, they need a Howland.
If there is a flashback he might also be the one to rally the north to Snow.