It is my understanding that the hardcore one is the Autumn helicopter hunt. The cold weather one, you can snowmobile until you find the animals and then sled them out. The only real hardcore part is the cold, which I would have to admit is likely quite brutal.
That said, the helicopter hunt is for a camp without a quad or snowmobile and no generator in camp either. Plus, you are walking on thawed tundra, which is harder going that frozen tundra due to the ground being so spongy. It is still somewhat cold, but not the brutality of the Greenland winter.
Hardcore weather vs hardcore physical work, so I guess they are both hardcore, just different.