Digging into Nemui’s archive, I’ve come up on this story by Konchiki. It starts off with a woman telling a story to man about a wife that froze to death during a snowstorm after her husband left home to get supplies. He never returned (died in the snowstorm). It turns out the man is in a similar situation and is caught in a snowstorm. He was only saved thanks to stumbling upon the house of this woman. He wants to repay her for letting him stay, but the only thing she wants is his “warmth”. The man soon finds out she’s no ordinary woman. The story starts out a tad dark, but it has a happy, slightly humorous ending.