I have a flight with Iberia from Spain coming into JFK (New York - JF Kennedy) Terminal 7 at 9:15pm, and because of a change of plans I need to book a flight to Atlanta from there. However, there are no such flights departing after that.
If I book a Delta flight from T4 for the following morning, could I just check my bag all the way to Atlanta from origin, and go into the airside of Terminal 4 at around 11:30pm?
If that's not possible I could also transfer to LGA (New York - La Guardia) and fly to Atlanta from there the next morning. Which airport's landside area is best for a layover?
Will airport security have a problem with a 17-year-old sleeping there overnight?