Stuff for the Thule setting

Fog.  Lots of fog.  It gives atmosphere, causes issues with frost, limits visibility.

Ditto with precipitation.  Rain makes things miserable, causes issues with searching and exploring; summer snows can hide features.

An early winter means that returning home is dangerous, but staying through the brutal winter is likely madness.

Ice crevasses

Avalanche

Hidden pits and ditches

Pretty much total lack of vegetative food

Lack of wood for building, fires; must be imported somehow.  For fires, they may import peat, coal, dung, etc.

Polar bears

Reindeer

Arctic foxes

Walruses

Seals (a few varieties)

Whales

Narwhals

Various species of geese

Puffins!  (So adorbs…)

Frost giants

Yeti

Ice hags

Ice trolls

White dragon

Draugr and other undead

A snow witch who is animating the corpses of frost giants into Draugr

Giant furry snakes

Snow vipers (apparently, northern Norway has vipers!)

Remorhaz

Wind witches - minor-ish air elementals that blow ice, cutting flesh

Snow and Ice Golems