Well on my HKG-JFK (on CX but CO flies same route to EWR) flight the other day, we flew up over Japan, over the north Pacific, crossed the West coast between YVR and SEA and headed into JFK. The Great Circle Mapper indicates that this routing is nearly 900 miles longer (+11%) than the polar route. Presumably the 150+ mph tailwinds over Japan/Pacific make up for that.

My point -- the shortest distance between two points is not necessarily a straight line. Of course, I did not get the actual mileage of the flight, only the "shortest distance" mileage.