Even though they quickly passed through the airport by pulling strings, the journey still took at least four hours—two hours was spent in flight, while at least one hour was spent in the car.
After all, Crane's Cry was far away from Westron's cities. The dozen mile journey wasn't all that far, and an hour was the optimal travel duration considering the complicated paths.
And that's just reaching the mountain—they still needed an hour to walk to the cave where the portal was, since Charlie was