Hi Magnus.
Can we expect new gear like skis, snowshoes, and dogsleds for improved movement over the terrain? How is this going to affect day/light cycles, will there be areas affected by seasonal periods where it never really gets dark/light? This could all be really fun stuff that you don't often seen in traditional fantasy settings.
Somewhere we will need new equipment.
As for the light/day and stuff, I'm wrestling with that. It's important that I don't get caught up in making The Bitter Reach a climate simulation, but rather take on ideas like the one you suggest, to make it more "fantasy".
/M
since we only have the broad strokes about the world itself nothing says it needs to be a globe, having a sun god mad at the northern reaches so his power is lessened, or the world is on the back of a tortoise so the north is on a sharp curve away from the sun, or we're on a ring world and the cooling systems are working overtime, or it just is cold... so many possibilities so little time.