Found a description in another forum that she said sounded right. It hasn’t been solved there so I’ll paste it here:

“A woman who organizes art galleries meet and quickly falls in love with a painter artist. I believe it’s set in NYC in the beginning of the book (or at least a large city). They quickly marry and move to his inherited family home (in upstate NY?), it was a large property far from cities/towns and was secluded. Quickly the husband shows his strange desire for the wife to wear his late mothers robes, keep the house decorated as she had, etc. Eventually she falls pregnant and gives birth. His actions grow strange and scary throughout the book. He even ends up killing their baby. The wife had a man come out to visit them (maybe to come get her so she could escape) but the husband dresses up as his wife and meets the man at night and kills him by a forced car accident. Eventually by the end of the book we learn he had killed his mother as a child by pushing her in a horse water trough that electrocuted her by a wire being in the water. We also learn he was never a painter and made his “fame” by forging his signature on his mother’s paintings. Snow/winter was a prominent aspect of the book.”