The series is going to end with the revelation that all of the introductions have been Samwell Tarly minutely inspecting the situations and writing a comprehensive story of the time. (See the intros with all the scopes changing, the astrolabe, etc.)
He will be the author.
I think but don't know that all the dragons die and Westeros is setup for enlightment and a turn toward democracy. Dany may or may no die. Jon lives. The rest is fairly incidental but I think you'll see people like the Hound, Arya, Gendry, Jaime, etc. ready to get to work on see form of civilization.
Cersei and Euron are effed.
It will be an ending set up for the dawn of a new age.