I don't doubt that the show ending mirrors the book's intended ending, however a huge part of it is how you get to that ending, which they rushed and fumbled horribly in the show. Like Bran becoming King could work, but not when he basically shows up out of nowhere and nobody knows anything that happened to him or what he is capable of, he basically disappeared for years and when he came back he said a few nonsense things but wasn't involved in much of the politicing that could make him a viable candidate for King. Or Dany going full Mad King, after they spend seasons showing her trying to not be a crazy ruler but then suddenly snapping, instead of going through a series of harder and harder choices that turn out worse each time and drive her to more relatable desperation and violence.

At minimum they needed a full extra season and a full final season, if not more. But without GRRM handholding them throughout the entire plot they completely lost the path.