The winter king is outside the walls of the Starks castle, Breanne should not even be there because (the show changed this) Lady Stark came back as a southern version of the winter walking dead, she captured Breanne after Breanne released Jamie,,,Lady Stark hanged her about book 3. The winter king and his minions cannot cross water, that's why the Greyjoy sister returned to the Iron Isle, to build a fallback position.