Hidalgo is too far away from Mexico City! If they need to change the airport I think the best will be Toluca. It´s very near just 30 minutes by car and very nice airport. And not too far as Hidalgo.
By the way United946, Polanco is a great zone, and a great place to see planes in route to MEX (I live there)
Yo soy yo más mis circunstancias - J. Ortega y Gasset