I think the days of really surprising plot twists are over.
We won't see any more first string good guys dying off. Maybe second stringers like The Hound or Davos, Theon, Gendry etc. The most important good character to die now will be Jaime as he will have to atone for pushing Bran out the window in ep. 1.
There won't be a shocking, "downer" ending. Daenerys will not become the Mad Queen. The Dead will all be destroyed when Jon and/or Daenerys kill the Night King.
It's just going to follow the stereotypical "happy ever after" model with Daenerys and Jon becoming King and Queen, Cersei dying, Euron Dying, etc. etc.
Too many "simpler" fans who expect the happy ever after ending are watching and would be too angry if they did surprising things now.