On the whole question of D&D’s decisions when adapting ASOIAF, I’ve heard it suggested that DD’s least favourite of the books was ADWD, and it makes sense to me, especially as it diverges the most from that book out of the others. Dany gets a lot of her darker scenes removed, Tyrion’s depression is snarked at by Varys and removed in one line, and a lot of the ‘newer’ characters and moments are either cut, changed heavily, or given to existing ones. Do you think so too, or is it more complicated?

No, I think that makes sense. ADWD really complicates the narratives of Jon, Dany, and Tyrion by having them struggle with leadership and fail in the case of Jon and Dany, and by having them struggle with some very ugly psychological ramifications of murder of loved ones in the case of Tyrion. And D&D have never been one for genuinely complicated character arcs.

To be fair, I can see how AFFC and ADWD together might seem like a huge challenge to adapt, because the cast is at its most dispersed (although one can see with TWOW how the characters are starting to arc back together, with the Starks beginning to move back to Winterfell and the Martells and the Golden Company converging on Storm’s End and then King’s Landing) and D&D are primarily in the business of shooting scenes with multiple leads interacting. 

Not that they’ve done a very deft job of managing that adaptation.