PLOTIris Simpkins, a society columnist for The Daily Telegraph in London, still loves her ex-boyfriend, Jasper Bloom, despite the fact that he cheated on her and is emotionally needy. She is devastated to discover he is engaged and decides to get away for the holidays.
Amanda Woods, a movie trailer producer in Los Angeles, breaks up with her film composer boyfriend, Ethan, after he admits to cheating on her. She comes across Iris’ listing of her cottage on a home swap website and messages her. They agree to switch houses for two weeks starting the next day.
Iris has no trouble settling into Amanda’s large house, but Amanda decides she has made a mistake and plans to return home the next day. That night, Iris’ handsome book editor brother, Graham, drops by after drinking too much at the local pub and asks to spend the night. Amanda agrees and after they talk Graham unexpectedly kisses her on the lips, Amanda suggests they have sex since she does not expect to see him ever again. The next morning, despite having enjoyed spending the night together, they go their separate ways. That evening Graham meets friends at the pub for dinner and sees Amanda there, having decided to stay.
Iris meets Arthur Abbott, Amanda’s elderly neighbor and an Oscar-winning screenwriter from the Golden Age of Film. Over dinner, Iris tells him about her troubles with Jasper, and Arthur gives her a long list of movies with strong female characters to watch so she can become “the leading lady of her own life.” Iris convinces Arthur to be the keynote speaker at a Writers Guild of America West gala and exercises with him so he can walk on stage without his walker. She also befriends Miles, a colleague of Ethan’s who is dating aspiring actress Maggie. While at the video store looking for one of the movies on Arthur’s list, Miles catches Maggie with another man. Iris explains her troubles with Jasper and they have dinner together to bring each other’s spirits up for Christmas Eve.
Amanda opens up to Graham, telling him she has not cried since her parents divorced when she was 15. She surprises him at his house and discovers he is a widower with two young daughters. He explains that he kept his daughters a secret because compartmentalizing his life helps him deal with the overwhelming responsibility of being a single working father and because he does not want to bring a woman into the girls’ lives unless he is sure the relationship has a future. They begin to think their relationship is more complicated than they can handle.
On the day of the screenwriter’s gala, Maggie asks Miles to take her back, but he refuses. Jasper surprises Iris by showing up at Amanda’s house, but Iris, drawing on the example of the women from Arthur’s films, kicks him out. At the gala, Arthur succeeds in walking onstage unassisted and Miles asks Iris out on a date for New Year’s Eve. She agrees and kisses him. Meanwhile, Graham tells Amanda he has fallen in love with her and while she does not return the sentiment, they agree to try to make a long-distance relationship work. While heading to the airport, Amanda breaks down crying. She runs back to the cottage and she and Graham make plans to spend New Year’s Eve together with his daughters.
On New Year’s Eve, Iris, Amanda, Graham, Miles and Graham’s daughters all happily celebrate at Graham’s house.