There's no canonical answer as to who the winner is. At least not yet. The reason why is obvious and the answer is gameplay.
I'd however expect NPCs like Delaryn and Sira to truly be dead, whereas characters like Rokhan, Lliadrin, Eitrigg, Turalyon, Danath and Muradin might survive the cut, even once we finally find out who the canonical winners of each individual warfront are.