My immediate response was F the Starks they're too dumb to root for. Even though Jon's plan was doomed to failure, it was at least a plan. He abandoned it, falling directly into Ramsey's trap, which Sansa had just warned him about. I would have been okay with him being trampled by the Bolton's, thereby becoming another Stark murdered by their own stupidity.
If Sansa had told Jon about the Vale army he might have incorporated them into that failed plan, and maybe still have been slaughtered. He wasn't listening to what she was saying, so I've forgiven her for not telling him.