I think Sansa obviously wants to go South to take the Freys and of course King's Landing and the Lannisters. Jon will insist on focusing on the Night King. Frankly he doesn't really give a shit about being King of anything let alone Westeros. He wants to defend the North from the Others. Sansa needs to convince him that the only sure way of doing it without being ignored like he was for most of the series is to become King of Westeros. I think that will be the heart of the conflict between the two next season. It would make sense for that to end with Littlefinger death and Jon being forced to go with Sansa's plan because the Wall is going to fall and Jon has to retreat South. I think Bran causes the Wall to fall somehow and joins back up with Sansa and Jon. On way South they will also pick up Arya which would reunite all the living Starks. Bran can also tell Jon his parentage which would cement his claim to the throne.
Dany will come at King's Landing from the south with a completely fucking stacked deck. The entire Dothraki clans, the Unsullied, all of Dorne and The Reach AND three motherfucking dragons??!?! WIth BOTH Varys AND Tyrion advising her? I mean are you kidding me?
Not sure if the series was as clear as the book but we know from prophecy that Cersei will be killed by Jaime and supplanted by Dany. The only thing I'm unsure of is whether Jaime survives. My instinct tells me no
Ultimately I do think Jon and Dany join forces to beat back the Others and marry but it will be political. I think Jon remains in the North to rule there as her Warden because he feels he owes it to his people and the wildlings. Dany stays at Kings Landing as Queen but can't be with Jon. So that will be bittersweet ending GRRM hinted at.
I think Tyrion as sole surviving Laninister will get Casterly Rock and be Warden of the East as well as remain her Hand. I think it would be very ironic if Sansa wound up marrying Tyrion anyway which would be the biggest play politically and also serve to unite the two most powerful families that had been deadly enemies before.
Anyway just my thoughts on what could happen in the home stretch.