Grand Central, Bryant Park’s Winter Village and the Fifth Avenue windows; see the Rockefeller tree after dark.
Day 2
Central Park & museums
Morning at the Met or the Natural History Museum, a park walk, then skating or a Broadway show.
Day 3
Downtown
Statue of Liberty ferry early, the 9/11 Memorial and the Oculus, then the Brooklyn Bridge at golden hour.
Day 4
Villages & the West Side
The High Line to Little Island, Chelsea Market lunch, then West Village streets and SoHo shops.
Day 5+
Go deeper
Brooklyn for Williamsburg and DUMBO, Astoria for food, or a Hudson Valley train to Dia Beacon.
Honest thought: December days are short and crowds peak near Christmas. Book timed tickets, plan indoor afternoons and save the light displays for after 4.30pm, when darkness falls.