Wow, maybe they were at JT's house? I guess they spent a white Christmas in Big Sky, Montana! 

Even though they have publicly separated they still take family vacations and trips together, and they proved that this Christmas. According to People Magazine  "They had a nice Christmas," a source tells PEOPLE, adding that some relatives joined the former couple and their three children, Violet, 10, Seraphina, 7, and Samuel, 3, at the private, members-only ski resort in Big Sky, Montana, where the family arrived Dec. 21.

Of course the folks who were in the know said Ben and Jen prefer the enjoy the privacy of Montana. Probably why no one actually spotted them here too much anyway.

I guess they stayed in the same house but in different rooms on the same property in Montana. Hopefully they were able to relax a bit in Big Sky country.