So, has anyone seen these hats drop in normal modes of the WOTLK dungeons this year?.........You necroed this after the event closes? And no, they only dropped in the Heroics.
If any of the three pieces of your Winter Garb set have 0 durability, you won't get the achievement. Every stored piece of Winter Garb I had in the bank, personal or Guild, had 0 durability when I took it out. I suspect Blizzard decayed stored Winter garb, there's no way they were damaged while I wore them in previous years. Don't waste Graccu's Mince Meat Fruitcake, Repair your Winter garb before you choke down the fruitcake!