I grew up in New England, so I know a little aobut your weather patterns. I think most of the generic phals ("Moth orchids" that you see in the big home & garden stores are fairly tough. The thing is, they are native to parts of the world where the weather does not vary that much from season to season, and so they like to be in stable conditions.
If I were you, I would check the area of the orchids for things like drafts and exposure to sudden changes, and try to find a way to compensate for that. They like air movement, but not temperature changes except for the usual drop at night.
Do you have central heat or radiator heat, or woodstove?