You should contact the guys at Skotfélag Austurlands (aka SKAUST) and they'll most likely hook you up. They have a beautiful range, but it's almost an eight hour drive from Reykjavik.
(If I recall correctly their range goes out to 500 meters.)
Ya, I get it. You can definitely look at it from that angle. But another member invited me out to his place to shoot 2,400 yards. Now we talk every single day. You never know until you ask.