Nothing compares to the magic and excitement of the holidays in New York City, where the streets blaze with lights, windows dazzle and a special box from Tiffany could change the course of a person’s life. Or several lives. Rachel and Gary (Zoey Deutch, Ray Nicholson) are happy enough but not quite ready for that big commitment. Ethan and Vanessa (Kendrick Smith Sampson, Shay M...…