I had thought it was a rebloomer, but your mention and something I saw in print is making me doubt my memory. Mine came back fabulously, and Houston is not prime hydrangea territory. I have it in a large container on the edge of my shade porch on the sheltered side of my house. It's kind of funny, it just hit me when I started to comment that all the blooms are on one side of the bush, that it is the sunny side. Probably not coincidental, huh?
Anyway, I like it a lot, and maybe I'll post some pics when the flowers open fully.