re: GoT: Do you think Westeros is 'destined' for some fate? (spoilers)

In any conventional story, the protagonist(s) is/are destined for some end. Everything they do takes them one step closer to it.

If, for some reason, the Boltons, Freys, White Walkers, etc. "win" in Game of Thrones, and they are the ones left standing at the end, then you have to question whether the story was ever about anyone else other than them.

And if it was, then why?

It would be exceptionally weak storytelling if, somehow, the antagonists or ancillary characters are left standing at the end, with little to no development into them over the course of many books.

I think ultimately, despite the many twists and turns and bad things happening to good characters, Martin will follow convention and have one or more of his main protagonists finish the series on top.