Ramsay Bolton
Our Blades Are Sharp!!
doubt it, they havent even hinted at the stark kids being wargs, but they showed Bran doing from early on.
Would be cool to show her still connected to Nymeria tho especially when she goes to Bravos.
I wonder then if they will just have Cat's corpse wash ashore and the Brotherhood finds the body that way, which would be a letdown.