I could talk for days about High Sparrow theories. Some strong circumstantial evidence out there on his (eventual) role in the show.

As for the Boltons, I think they're going to be a slow burn. At the end of the day Martin still roots for the good guys, and he's (hopefully) got some twisted shit in mind for them. I mean, even though everyone was rooting for Arya to kill Joffrey, he did go in pretty horrific fashion.