In order to get back to POP from Coranado Springs you have to take a bus to the nearest park (that is still open, AK closes the earliest)and then transfer to a POP bus.
As someone else suggested you may want to eat at a monrail resort (Contemporary, Chef Mickeys or Concourse, Polynesian, Ohanas or Kona or Grand Floridian, Park Faire or Grand Floridian Cafe) restaurant, that way you can hop the monorail to MK then take the bus back to POP.