I think it might be a two pronged attack. The army of the vale will attack them in the back without even knowing about the wildlings' attack.
Or they end up fighting each other, Ramsey wins and captures Jon and Sansa. Always consider the worst case.
You mustn't be afraid to dream a little bigger, darling. The fortifications of Winterfell fall to the Wildlings and the Starks. At the point of victory, tragedy strikes when the Vale and the Iron Isles take advantage of the weakened strength simultaneously, but not cooperatively. Theon falls off a boat and drowns. Littlefinger executes Jon and takes Sansa as his wife, claiming the title of Warden in the North. Meanwhile, Dany brings her army of Dothraki to Westeros, where they just happen to arrive at the same time that the Wights bring down the Wall. An epic battle ensues and Dany loses. The Wight army now has a legion of undead Dothraki and dragons. They overrun the kingdom. Cleganebowl never happens. We never find out what makes Pod so special to the women at King's Landing. Gendry's boat is found and he's killed after years of rowing. Arya finds Needle and loses her eyes again, this time due to bad sword safety. We get our first full graphic sex scene, but it's Melisandre without her necklace on. I'm talking full penetration. For an entire episode. Maybe two if she's got the stamina. Bran becomes a tree and is promptly chopped down for firewood. Rickon lives but nobody cares.
I watched the ending again. That's some of the most clever edit writing I've ever seen. (Edit: Removed previous reference to what happened since I didn't spoiler-tag it.) Anyway... Spoilers, to explain what happened, for those unsure (it can be convoluted so I'm trying to be as simple as I can; feel free to correct me if I mess anything up): The Three-Eyed Raven knew what was going to happen. He knew Bran was touched by the Night's King – that's why he didn't seem at all surprised and immediately disbelieved Bran when Bran said he didn't know whether or not he touched him. Bloodraven knew. That's why he took Bran into the next vision, which seemed benign at first; he knew this was the moment in which Bran and Meera would destroy Hodor's mind. Over on Reddit, a lot of people are complaining that it doesn't make sense or they're simply having a hard time wrapping their collective head around what happened. It's pretty simple, to be honest. The first time we see Bran "changing" the past was when he called out to his father at the Tower of Joy, only Bran didn't change the past – he was already there and did call out to his father, and his father did hear him in the past. That's why he stopped and looked around. That actually happened in the past; it wasn't Bran altering the past. (A similar thing happens in the books when Bran taps into a weirwood tree that I believe Theon is near. Bran calls out to Theon and Theon hears him. It wasn't Bran "altering the past," because it actually and already happened.) Bran isn't experiencing "visions" in the traditional sense of the word. He's experiencing things he's already experienced because he's already been there to make those things reality. He can "change" the past because he's already "gone back in time" to the past to do those things. It's sort of like how Harry knew he was able to cast the enormous stag patronus in Prisoner of Azkaban – because he'd already done it. He knew he could do it because he saw himself do it. Now, in the case of Hodor: Bran heard Meera shouting at him to warg into Hodor, and Past-Hodor just happened to look at Bran at the same time. This allowed Bran to warg into Past-Hodor in order to take control of Future-Hodor – because it had already happened. At that moment in time, Bran had already taken control of Past-Hodor in order to control Future-Hodor. Bran wasn't in a vision of the past: He was experiencing that event in real-time. Past-Hodor's seizure was caused by his mind being absolutely unable to comprehend that Bran was controlling him and that he was in the process of being torn apart by wights, and he continued to hear Meera shouting "hold the door," which was all he heard aside from the chattering and screaming of the wights. So Past-Hodor's mind was broken completely, explaining why he was always so jumpy in certain situations. He had a vague idea of what his death would be like, but because Bran had partial control of his mind, he didn't fully comprehend his death, and so was never quite sure when it would come. That's why Hodor has that mild breakdown right before Bran takes control of him, because he finally realizes: This is the end. This is what I saw all those years ago. So the Three-Eyed Raven knew Bran would tap into the weirwood network without him and knew he'd have to take Bran to that specific spot for him to warg into Hodor, because it had already happened. He also knew that would be when he died and when Bran would become the Three-Eyed Raven himself, because it had already happened. TL;DR – When Bran goes back into a "vision," he's not experiencing a "vision," he's experiencing an event that has already happened. Everything he does in one of these "visions" is something that he had already done, or else he wouldn't be in that "vision" doing it in the first place. When he invades Past-Hodor's mind to take control of Future-Hodor, he had already done that, or else he wouldn't have been in that "vision" to do it. Edit – Someone on Reddit explained it perfectly: When Bran experiences these "visions," he's actually in two places at once on the timeline – in the "past" and in the "future." Bran is transcending time and space. Edit 2 – Turns out GRRM told the writers what happened to Hodor and Hodor's actor Kristian Nairn several years ago. So holy god damn.