The extreme north of Westeros is intentionally left very vague, and no official map of the the fictional world shows where the continent ends. This is presumably because nobody can survive that far north, to chart a map, but also lends a lot of credence to the theory that White Walkers have been around for ten thousand years in that uncharted territory, minding their own business.
Also, the first clue we get that the Bloodraven is a piece of shit is when Bran falls from the tower. The crow is what lured Bran up the tower, causing him to be pushed off. He immediately starts having dreams of flying instead of being a wolf, and to him that seems strange. Bloodraven will probably turn out to be R'hllor who is the only "God" that has shown any power. The position of the 3-Eyed Raven gives a person the ability to change the past and present, but also to see the future.
Bloodraven molded the world, knowing how events would unfold into the future, by introducing prophecies, dreams, and subtly manipulating people.
It's likely this whole thing ends with a renewed piece with the Whitewalkers via Bran, or something along those lines. I mean now that we know that Bloodraven and Bran can alter the past (to a small extent), it adds all sorts of fucking possibilities that you really can't take reliable guesses at. Hell, humanity could be wiped out in Westeros, with the CotF re-emerging from their long forgotten burrows. We'll just have to wait and see what Bran does with his powers, but he's the real character to watch. Everything we've seen so far is set in stone, meaning it can't be changed. If someone "saw" Bran, it'd be represented in the show... but someone says that may just have happened here:
Does this scene prove Bran time-traveled back to Ned Stark
I'm only saying that Bloodraven is probably the true puppetmaster who has set the story in motion (i.e. Littlefinger with god-like powers), and the White Walkers are no less evil than humans, perhaps even less so.
There's a reason we know so much about Bloodraven's previous life before him becoming the 3ER. We know more about him, and his personality, than any other character in the series. Why give us so much information? And why are D&D lying by saying that the White Walkers don't communicate, speak, or do anything because they represent death and nothing more? That's clearly untrue based on their relationship with Craster and the probability that the first Long Night ended with a truce rather than their extinction. Craster killed his children, the White Walkers did not.
They are clearly very intelligent and care about their own survival as they only attack themselves when:
* assassinating Waymare Royce (which the books describe as looking almost exactly like Jon Snow)
* attacking Sam who has the Horn Of Winter
* attacking rangers at FotM where Jon Snow is.
* attacking Hardhome at the exact time Jon Snow arrives, again. A Whitewalker itself attacks Jon. Why him? There were like 20,000 people there.
* attacking the cave of Bloodraven with Bran inside.
Why do they only come in force at certain times? Mance said they'd "stalk" his camp and pick off stragglers, but they never attacked his army, when they could have wiped him them out due to wildlings not having
anyweapons which could kill them. They'd have 100,000 more wights now.
Why do they only really seem to launch a massive attack/ambush in these five instances? Why were the wildlings largely left alone for nearly twenty years? GRRM is a careful writer, he hasn't added random shit to this story just to produce dramatic tension. There has to be a common link between the five.
They clearly wanted Sam's horn (another clue that it will bring down the wall), and they really, really, really want Jon Snow (Jon Snow look-a-likes) & Bran (or someone else inside the 3-ER's cave - Bloodraven, Leaf, or even Meera) dead. That much is obvious.