Harley rallies her siblings and parents to take a trip to Florida to celebrate Christmas with their abuela, but in true Diaz fashion, things go awry. One rerouted flight, an unintended pit stop and a damaged rockstar tour bus later, the Diazes find themselves stranded in a small town without phones, credit cards or money, where they must compete with the town residents in an “Iron Elf” competition to get their bus repaired and make it to Abuela’s in time for Christmas.

Under Abuela's watch for the weekend, the Diaz kids are committed to making her visit disaster-free, that is, until Harley learns that Ethan spilled her deepest secret.