I'm pretty sure that Mad Queen Daenerys will happen in the books as well. D&D said that besides the deaths of Hodor and Shireen, there was one more plot point that GRRM shared with them that shocked them and I believe this is it. Although I'm sure it won't be as rushed in the books. I'm actually not bothered by Mad Queen Dany, I just wish they had allowed more time to build up to it. When you think about it, Jon and Daenerys only met 9 episodes ago. I actually liked the pace of season 7 but this season has been far too rushed. Even though I've had my share of disappointments, I still like season 8. Including Episode 5.
That's what I've said. GOT at its worst is still better than most shows at their best. But I think 8 seasons, 10 episodes each would have worked. An additional 7 episodes to tell the story would have been enough.