For some reason I cannot reply to your PM. in a normal fashion. As to your question I have never harvested a really old Mugo but I have dug them from a nursery in Augjst when the temperature was 110 and the tree did fine. Three years later I killed it repotting it in a spring for a demo. Go figure?!
I actually didn't take any photos at the convention dear... I was in the vendor area the whole time helping out Daniel and omi. :) There was some great stuff though... that much is true. Venue was a bit of a bummer for a lot of our older convention goers... but lovely.