IMO season 5 and season 6 of GOT were just not that good. Hardhome js a highlight sure but they were both poor and I don’t know if we’ll ever find out but I don’t believe Cersei blowing up the Great Sept (I thought this was pretty weak in GOT) is a plot point in GRRM’s story no do I believe his plan is to end with Bran as king.

There are entire storylines that GRRM has the showrunners eliminated that lead me to believe that they were mostly on their own even if they had broadstrokes of the ending. And yes these storylines have made it difficult for him to ever complete his work.

As for HOTD I own Fire and Blood and have read it multiple times. I don’t mind filling in the characters as the source material is more lacking than GOT but Condal seems have taken all the worst excesses of GRRM for pure shock value.