Aaaah, yes! I love FROST for FO4 - to be honest, that's the only way I ever played FO4, the vanilla game bored and annoyed me to death after just a few short hours. I'd love a "post-apocalyptic" version of Skyrim, e.g. in an alternate scenario where Mehrunes Dagon won the Oblivion crysis, or where the dragonborn didn't exist and the dragons laid waste to Skyrim and re-enslaved the population. Dozens of other ideas come to mind but those are the ones for which we already have quite a lot of lore information and wouldn't require a completely new worldspace. And with the same scarcity and hardcore elements that FROST has... that would really make the game feel brand new, and offer a completely new experience. But in the end... this idea does still fit the Fallout series more than TES. There they are lore-friendly, but here, not at all. And you can't really have anything similar to FROST if you have the same settlements full of merchants and peace of which you can take advantage of... the best you could do to make it lore-friendly would be to have it happen right after or during the Great War, but since Skyrim wasn't directly affected by it, it's still not quite enough.