I can't really tell you exactly but I have let out 5,200ft of Dracon on my kites and they go so high that all you see is a period in the sky .... I'm assuming mine have flown close to 4,000ft if I take out the droop of the line...... Thats pretty high! By the way, the higher the kite goes, the more stable it becomes and the more wind it encounters......by winds can change direction drastically .... I was letting out string on one of my kites once, the wind was blowing south east I think and then I don't know what happened...the kite must have entered a layer of wind that was about 96 degrees from were it originally started it it was weird watching the wind blowing south east and the kite not flying in that direction!
Until it reaches the point when Lift" is negated by the weight of the string and tail. I personally have had about 500 feet of string out and the kite string broke and it just flew away.
It can fly as high as the length of the wire which is attached ti it.