Our take
The ironic title says it all: a snowy Christmas plan undone by unseasonable warmth. It is light and loose rather than a classic, but the A.V. Club found its pacing better than almost any episode that season, and Andrea Martin is a gift as the stranger already in the cabin. The haunted-room gag and Haley and Andy's secret coming out tie together neatly, and Alex and Fig's Silent Night makes a lovely closer.
What happens
Gloria wants the picture-perfect snowy Christmas she has always dreamed of, so she rents a mountain cabin for the whole family. On arrival it is warmer there than at home: she had read her weather app in Celsius. Worse, an eccentric woman, Fig, an astrophysics professor, is already staying in the cabin and ends up spending the holiday with them, striking up a friendship with Alex, who is trying hard to get into the Christmas spirit. Mitchell and Cameron rehearse a big duet to make up for last year's carolling flop. Manny and Luke try to frighten Lily with tales of a ghost in a locked room. Jay announces he is retiring and handing his company to an outsider, a test of whether Claire really wants the job, and it backfires. Meanwhile Haley and Andy cannot keep their hands off each other, and when they slip into the locked room, Lily's scream in the middle of the duet brings everyone running. Gloria then surprises the family with a visit from Andy's fiancée, Beth.
Can the kids watch it?
Likely fine for children of about 10 and up, but we found no BBFC rating for this episode, and one storyline involves a secret romance being discovered, so check before younger children watch.