A Christmas Too Many (2006)

After 10 years of family squabbling, the Myers family returns to California to spend Christmas with the family matriarch to patch up old ruins. With the whole family in attendance, what starts out as a nice family event goes comically wrong when Grandma dies and the family, all afraid of ruining Christmas, refuses to acknowledge her death. Further complicating matters, everyone thinks that cousin Sonny, who seems to have Mafia related ties, has offed Grandma to get ahold of her fortune. When Sonny's Mafia friend arrives, it becomes everyone's job to try to make Grandma look alive, to save Christmas--and, they think, their lives.