One of the first places to celebrate the arrival of 2015 was Kiribati, a small island nation very close to the equator in the Pacific Ocean. The antipode of Kiribati is a city called Bandundu in the Democratic Republic of the Congo.

If I catch a flight at exactly midnight in Kiribati, and we assume my plane flies at a constant altitude of 40,000 feet, can I get to Bandundu in time to celebrate the New Year?

Is Bandundu the hardest (meaning requiring the highest average speed of travel) place to get to from Kiribati in time for New Year?  Where would be the easiest? Why?