I disagree with a lot that has been said here.
I saw an interview with D&D and they said they knew that if they were to do everything they wanted to do in the final season, they would only be able to make 6 episodes. It definitely isn't down to being lazy and not being bothered. Quite the opposite. They are essentially making 6 movies rather than a TV show. That's huge! The production in this last season has been immense. They've been making ground-breaking TV.
Bran had a vision of a dragon shadow over KL and Dany had a vision of the destroyed throne room, so the destruction of KL has definitely been in the pipeline for a long time.
Every interview I have seen with the cast they have been overwhelmingly positive about the final season.
Of course the final episode will wrap up most of the characters storylines. I'm pretty sure we will hear from Sansa, Robin, Brienne, Tormund, Bronn, Yara and Ghost. I think Varys letters were to all of them to rally and fight for Jon.
I liked Jaime and Cersei's ending, I thought it was appropriate that they came into the world together and left together.
The actor who played Euron had such fun with his character. Jaime lost his sword hand. That's why Euron could defeat him. Bronn said that Jaime was easy to beat now.
I loved Arya's storyline this episode. She went from being the bad-ass who killed the NK to be almost killed with the common people. I can't wait to see what she does next. I agree she could be the one to kill the final dragon with her special weapon, but I have no idea. She's there to do something!
The whole theme of this season (the eire show) has been that you cannot rule through fear. Dany has always been an excellent conquerer, but not such an excellent ruler. She never managed to rule Mereen properly and was always on the outs there. Jon has always been able to lead. Tormund said that Jon could made an ally of his enemies and there is a lot of truth in that. Jon's power is in his ability to bring people together. Dany has never been able to do that.
I don't think Tyrion would make a good king. He was terrible when he was Hand to Joffrey. The people hated him. He hasn't been so great as Dany's Hand either. He is a perfect example of someone who is book smart, but he's not a popular person.
Anyway, I am ridiculously excited about the last episode next week, but also sad that it has to end.
Also, I don't think HBO has anything to worry about. I'm really excited about "His Dark Materials" and "Catherine the Great" coming this year. Plus there are GoT spin-offs in the works.