It Came Upon the Midnight Clear 1984 ( 5.6)

Retired cop Mike Halligan decides to show his grandson, who has never seen snow before, what a real white Christmas in New York is like. But a sudden fatal heart attack derails those plans, and Halligan makes a deal with the Archangel of Heaven to return to Earth for a week until Christmas in order to give his grandson the seasonal glories of New York City.