I don't know how the show will have time to explain 3ER/LoL/NK endgames in 5 episodes when they didn't even lay any groundwork for it in E1. Maybe the writers don't care.
I get the feeling they might actually end the whole White Walker thing in the battle of Winterfell, and then deal with the fallout for the next three episodes.
Either way it's gonna be some major bullshit/gigantic deus ex machina asspull. And I'll enjoy the ridiculousness on display.
As a side note: Does anyone really know for sure how long a person's severed head remains alive after being separated from it's body? Are we sure they virtually die instantly? I would think there might still be enough blood/oxygen in the brain for it to remain alive for a least a few seconds
Fairly certain you remain conscious long enough to realize you've been beheaded.