How large is the Ga' Hoolian world generally?

I believe that from the southernmost tip of the desert of Kuneer to the northern glaciers of the Northern Kingdoms the distance is approximately 1,800 miles based on a reference that flying across the Unnamed would take a night, a day, and half another night, অথবা the same amount of time it would take to fly the previously stated distance. If the owls are flying at 40 to 45 miles per ঘন্টা that is about how much distance they would cover, but I am still in doubt because of a reference in The Journey to the Band overshooting the Great Ga' Hoole বৃক্ষ দ্বারা 500 অথবা so leagues. Anyone know any other recourses to find out the size?