In general, I would assume that any villagers living in a house would try to get rid of the snow that would enter their house through their open windows and door ways. With that being said, snow shouldn't be in the house covering everything, especially the actively burning fireplace of all places. Even their food in their house gets covered in snow. Perhaps adding doors and hide covers for windows could make the houses look more complete and better at staving off snow from entering and blanketing the inside of the houses. This also goes for any other building, in general, that has a room, like the barn or warehouse. Hope this might get placed in a coming patch, if anyone else has any input on this, I would love to get other opinions on this topic.