What will be the Darkest Point in the Winds of Winter? (Spoilers Extended)

George has had the following things to say about the Winds of Winter:

Question about "The Forsaken"

GRRM: “Yeah, that is a dark chapter. But there are a lot of dark chapters right now in the book that I’m writing. It is called The Winds of Winter, and I’ve been telling you for 20 years that winter was coming. Winter is the time when things die, and cold and ice and darkness fills the world, so this is not gonna be the happy feel-good that people may be hoping for. Some of the characters [are] in very dark places…In any story, the classic structure is, ‘Things get worse before they get better,’ so things are getting worse for a lot of people.” -SSM, Spanish Interview: Guadalajara, 2016

Spanish Youtube Video

and:

The number of POVs will be declining throughout TWOW. GRRM does not intend to add any more POVs. In fact, the number of POVs is about to decline. “Take your bets,” GRRM warned.

Tower of the Hand Summary

There are numerous other links, most of them can be found in u/BryndenBFish's Ultimate Winds of Winter Resource all showing GRRM stating how there's going to be a ton of deaths, POV's disappearing, etc.

My guesses are:

• Shireen being burned alive by Mel/Stannis or Mel/Selyse in order to "wake the stone dragon"

• Brienne dying to save Jaime from Lady Stoneheart

• Bran's story taking a dark turn

TLDR: Out of everything that could happen in The Winds of Winter, what do you think will be the darkest point?