In Cloverdale, Massachusetts, optometrist and self-proclaimed Christmas expert Steve Finch (Matthew Broderick) wants his kids to have a great Christmas, filled with traditions such as using an Advent calendar, taking Christmas card pictures in matching sweaters, and buying a large tree. In the middle of the night on December 1, new neighbors move in across the street: car salesman and electrical engineer Buddy Hall (Danny DeVito) and his trophy wife Tia (Kristin Chenoweth), whom Steve meets the next morning. Later that day, Steve's wife Kelly (Kristin Davis) and her daughter Madison (Alia Shawkat) and son Carter (Dylan Blue) go to the Hall house, where they meet the Halls’ teenage twin daughters, Ashley (Sabrina Aldridge) and Emily (Kelly Aldridge). Tia and Kelly immediately become friends, as do Ashley, Emily, and Madison.