I've read several interesting bio's on him, but I can't locate them now, to post a link
. As to" where" an iris reblooms, I've noticed, quite often, that some will rebloom, here, in 5a, and DON'T in "higher zones"
....I believe some need a "cold trigger" to spur rebloom, while some need a certain amount of "day length", anyway, it's still a long way from being an "exact science " !!