I'm posting this after ed, obviously, but I'd say the same thing: as a Northern Hemisphere three-year-old, he has a much greater chance of lasting the 3200m. than a Southern Hemisphere sophomore.
Oh, the trip will be no problem. He has already won over the trip (Queens Vase at Ascot). My concern would be his inexperience, that's all. He never ran as a 2yo, so he has limited racing experience.