I guess the problem with shows like Lost and Game of Thrones is that they're shows of the moment, leaving everyone talking and theorising and wanting things to go a certain way. They ought to just stop making them right before their final seasons and pretend they got cancelled. Anything else will end up disappointing most people.
I'm rewatching season 6 for the first time, doing what I'd done every year before that - an episode, then the episode with commentary, then the next episode - and even though it was starting to pull things together after slow-going in season 5, I'm still feeling the strain of the lengthy storylines. Arya's bullshit blind beggar adventures, Daenerys twatting about with the Dothraki. IIRC it picks up a lot of steam by the end and proper levels off again in season 7. I remember finding it odd that they had some perfect opportunities to lose characters who didn't need to be around anymore - Bronn in the fight with the dragon, most of the gang who went up to catch a white walker - but seemed really afraid to do so.
It'll just be interesting to see, if we ever actually do, how close this comes to GRRM's ideas. We've all heard the stories about him welcoming the team into his mansion to share the end of the story with them, but how true that is, how much he showed them, how their interpretations of that stuff has differed, is all up in the air.