I have hit 17,000 feet twice and both times I had it back to me with around 30% battery so I could have gone further. Just wasn't in the mood to push it with a new drone. This is flying W/NW into a slight breeze with ideal terrain and almost no buildings in the area of the flight. Flying in less than ideal terrain and/or near lots of buildings substantially reduces the range I get.
I once hit 16,000+ on my Mini using the same flight path, but that time I had to emergency land in my uncle's farm field about 1,000 feet short of home.