A family gathering in the Castkills in February. Just remember it's probably goingto be real cold, really cold.
As others have said, flying into any of the New York airports will add an hour and a half onto the drive to get there.
You can fly into New York and take the commuter trains to 23 miles from Monticello if you are getting picked up, the airport in Newburgh is about 50 miles, Newark about 110.