Dany's vision in the House of the Undying has always made me think the White Walker threat would extend to King's Landing. Yeah, Jon Snow ending up on the throne could be the interpretation of the specific vision she has, but that seems pretty obvious. The only thing stopping Dany from getting the throne at this point is in-fighting between her and Jon. The Golden Company ain't doing shyt, against two dragons. shyt the Platinum or Diamond Company ain't doing shyt, either. Reverting to fighting over the throne seems really anti-climactic to me. I also think Cersei should pay for her hubris in the face of the White Walker threat. While she has her own prophecy that's still in play, I think that can work in conjunction with the White Walkers still being lithe overall antagonist in the end.