The first set ever to be made under what we would term as a "block system" was Ice Age: Set on the Dominarian continent of Terisiare, the concept of the sixth Magic expansion (released in 1995) was that centuries after the Sylex Blast in Argoth that caused Urza to ascend to planeswalkerhood and his brother Mishra's army to be destroyed, the climate of Terisiare changed to perpetual freezing winter. Players loved the idea of cultures struggling to survive in this Norse-themed setting, and the set was full of fun and powerful cards and the follow-up, Alliances, is perhaps even better-liked today for its forward-thinking multicolor theme.
Unfortunately, Homelands was released right after these (meaning this mechanically poor set, which took place on an entirely different plane called Ulgrotha, deprived the playerbase of a conclusion to the block). Coldsnap, of course, purported to be the "lost third Ice Age block set," and the original Terisiare block story was seen to a conclusion, but that set was mechanically lacking, and for various reasons we probably won't be going back to that precise setting in the near future. Still, "cold northland" is a venerable fantasy trope that's well-recognized but still holds a lot of interest, because Vikings are just that cool, and Mark Rosewater answered a related question quite positively on his Tumblr blog recently.
When esrix asked, "Will we ever see a frozen plane again? Not necessarily snow lands, but a plane like Hoth? We need more penguins is what I'm getting at," Rosewater responded:
Chances are high for a cold plane eventually.
The "Norse mythology block" proper (Ice Age took some influences from Scandinavia, but never really saw them out to the logical Ragnarok conclusion) is rather high on Rosewater's short list, so that could easily be the "cold plane" he refers to. Custom designers also rather like this trope; most notably, Guesswork's Dominaria block on MTGSalvation is based on the premise that all of the plane was once frozen over, and the Sylex merely returned it to its original state.