The Thursday before Christmas, I woke up in downtown Sofia, leisurely drank a coffee, and jumped on a metro that took me directly to the airport. In less than an hour, I was at the gate for my flight to New York's JFK. My plan was to get the last bus upstate that evening, so I could be in my own bed a little after midnight. But it would only work if the flight landed on time - and if passport control took under an hour and a half.