I’m pretty sure Winds of Winter is 1500+ pages of “Others chop people up, everyone dies!” and “Dragons breathe fire, everyone dies”, based on what he’s said about that and A Dream of Spring.
I don’t know that we’ll ever see them in full, but I daresay we’ll eventually find out, and I strongly suspect that if King’s Landing burns (and I imagine it will), it’ll burn in Winds of Winter. A Dream of Spring, I suspect, is going to be more the aftermath to that in totally unnecessary detail, potentially setting up countless sequels which will either never happen, or not be written by GRRM. I mean, it’s possible Winds of Winter ends with the battle at Winterfell, and then A Dream of Spring climaxes at the burning of King’s Landing, but I’m just really skeptical that even massively expanded, there could be all that much material between those two events. I mean, season 8 was 6 episodes, which were:
- Everyone arrives at Winterfell
- Preparation for battle
- Battle
- Aftermath and everyone arrives at King’s Landing
- Battle
- Aftermath
And of these novels, he’s said that between them, they’ll likely be over 3000 manuscript pages.
I’m pretty sure, too, that at this point, based on the sheer amount he’s written, that he’s actually finished Winds of Winter, and is just extensively tinkering with it.
It’s also possible that the ending will be almost entirely different, perhaps to the point of different characters dying/surviving/becoming king. D&D themselves said S8 was “mostly original material”, and only loosely based on stuff that GRRM had told them, at one point.