Given the last seasons, I think everyone should be prepared to be disappointed.
I think the last two seasons (post-book) will be vindicated if there is a satisfying reveal/tie-back as it relates to the White Walkers' motives and stuff like that. For example, if we learn for sure that the Night King getting the dragon was a trap and he knew (somehow) they'd be there, that makes that episode a little better, "critic-wise." Either way, I am excited for the return in the spring!
That is assuming George R. R. Martin remains alive and well enough to finish his Song of Ice and Fire book series. Looking at him and his age, I have my doubts.
