Well, I have the earlier mentioned bug, where if I get in the NAPA hatchback, I get carted through Novy Sobor, all the way to the church in Mogilevka, where the driver gets out, runs around the car a bit before stopping by the road, whereupon nothing happens for all eternity.
I've also tried calling the helicopter in after rejecting the NAPA aid offer, but it never shows up for some reason.
And, of course, I helped out the NAPA earlier in the campaign, which is why they like me now.
But from where I'm standing, Bitter Chill is unfinishable (unless you can take a car and try driving to Electrovodosk to somehow trigger the the next plot point that way?