What's with Vikings having the Greenland coast as a historical area, but it being impossible to settle due to being all snow? There's even names in the CNM for it, which sadly won't see any use.
In case it's open to suggestions: I know that historically their settlements there eventually failed, but the same can be said of Vinland. My suggestion would be for their historical area there to start as grassland ("green"land southern coast apparently was warmer than usual during the 800 - 1300 AD period), place some forests and maybe some food bonuses there, then after a certain date (1300?) they turn to tundra, and later to snow if we want things to get cool.
Here's a possible redesign of the area:
Spoiler :
Actually, iirc settling Greenland is one of the many strategy necessary for Viking to settle Vinland. I don't know if that ocean hopping strategy is still there, but last time I checked I need to settle Britain, then hop to Iceland, hop to Greenland, hop to Vinland.
I think the main concern behind this issue is while I believe we all aware of this, we don't know how will they get abandoned... despite the name of the parent mod is Rhye's and Fall of Civilization, imo RFC is kinda bad in representing a fallen city, an abandoned city, a failed city. The only way to really abandon a city is by razing it to the ground with bonus stability penalty; or unluckily lost it as you built it adjacent to a capital of a rising civ (Ayutthaya vs Angkor)
In other words, once you plant it; you can't uproot it, you have to burn it down.