Ok, first off, let me say that this bit is giving me the most trouble. I don't have all that much experience with setting fronts, because I haven't run the game all that much. Fronts were also the part that I needed the most time to get my head around the first time I read the playtest document, as funny as that sounds.
So yeah, coming up with new, setting-appropriate Fronts for this hack has been my biggest worry. Let me just unfold my thoughts so far...
Scarcity
I think the list is pretty good for Iceland, too. However, this is not a world falling apart, it's a world that hasn't been built up yet. So, remove decay, add cold.
Threats
Warlords are all good, I think they fit this setting as well. I just think they're far less common than in Apocalypse World. But that's no reason to really throw them out or change them, I think.
Grotesques
Ok, my first impulse is to remove Grotesques alltogether. My intent was to keep the supernatural dial as low as possible, probably at zero, and the historical dial high. So mutant-types and cannibals are out...but Disease-vectors or pain-addicts could work. And it's just too tempting to put in a Grendel-type as a Perversion of Birth or something of the like. Still, Grotesques are out. The good ones will be relocated.
Landscapes
Landscapes are great. Iceland is a harsh frontier after all. If you want to turn that supernatural dial up a bit Mirages and Mazes can easily work as the tricks of the Landsvaetir. Landscapes are a-ok.
Afflictions
All good. I don't think this needs changing.
Brutes
Much like Warlords, probably not as common as in AW, but perfectly acceptable.
Ok, so that's for the existing ones. Here's where the design bit comes in. I want to make a new group, called Feuds or maybe (Mistakes of) The Past or something of the like. It would include a few of the surviving Grotesque threats. Killed the monsterboy's dad years ago? Time to set that Revenge countdown clock ticking. That sort of thing.
Which makes me think that the MC's list of moves needs a new one: Announce Past Sin
Feedback most welcome.