There's not a single Death/Water item in Dominions

[Wauthan]

Or it might be that Cold 3 doesn't mean "dead of winter" but Northen Scandinavia type climate (The game got seasons after all).
Meaning it would be hell on the local tourist trade, but not so much on well motivated peasants ability to grow crops.
And nothing motivates a peasant to grow crops like the idea of surviving yet another winter on squirrel blubber.