Game Of Thrones Theories: 13 Epic Season 6 Moments Still To Come
2. The North Remembers, The North Revenges

The finale's title "The Winds Of Winter" has been the subject of a lot of theories as far back as George RR Martin's first announcement of the title of his long gestating sixth ASOFAI novel. The most compelling interpretation suggests that the title refers to the strength of the North, and to the vengeance the Starks and their bannermen will enact on those who wronged them in the South.
So, with Ramsay Bolton defeated, will we see Sansa turn her attention to her own kill list (replacing Arya's mostly redundant one)? The Starks have no quarrel with Danaerys per se (she might see it differently, given Ned's Tower Of Joy actions), but they have reason to wipe out both the Lannisters and the Freys, and there's no way they could ever allow the Red Wedding to go unpunished.
Will we see the end of the season affirming the Stark's intent to get their revenge? They surely can't just be happy to be at home again with so many enemies alive: maybe it's time they went back South (before making some allies in Dany's marauders next season?)
Likelihood: 7/10
The Starks will never thrive as long as their enemies live: that's the great tragedy of their existence. So while it's unlikely we'll see any actual action against the great Houses in the South, it's likely we'll see a declaration of intent from the North. It'll be great just to see the Lannisters' reaction to hearing the news.
And just maybe their defeat of the Bolton army will lead to the undeclared houses in the North rallying once more under their banner: because if they don't, they're going to find themselves facing the bigger threat of the Nights King on their own.