"...the PW site states they are hardy to Zone 6 (-10�F)."

I had H.involucrata for 3 years in my 6b and it experienced severe diebacks every winter. Of course it didn't bloom.
I gave it to a friend in a solid z7 (Long Island, NY) where it produced handfull of blooms this year.
Not familiar with this particular cultivar which might have better hardiness characteristics.
In any event, you have nothing to lose, try and see.

Wow wow wow what a great buy !I,m looking for two of those and I,m sure I will end up paying closer to $40 each for them. I haven,t heard of the lets dance Star Light. Is it a new release as well?

I have seen the Let's Dance®Series being offered by on-line vendors for a year or more, but they often ship rooted cuttings or liners.
According to the nursery that introduced them (link below), they were supposed to be in the retail nurseries this year.

That said, I have not found a single one of the series at any of the local retailers that carry the Proven Winners (PW) line! In fact, I saw no PW plants at all there, throughout the year.
HD is the primary retailer of PW plants in this area and their supplier may not grow the Let's Dance Series or grew tired of having to take back a bunch of dead plants!

Here is a link that might be useful: Let's Dance® Starlight Hydrangea

Let's Dance was available in my local HD this year.
Let's see how it will overwinter :-)

Thanks for the responses!
Since I'll be growing the Blue Bunny in a pot for a year or so, I will probably need to bring it indoors after the first frost.
Last winter was horrible for most of my macs and serratas. Springtime revealed lots of dead canes and some plants were killed back to the roots. Some of those in pots didn't recover. I didn't protect any of them, because during the past 20 years, I had never experienced that problem. No record lows were recorded, it was just an overall colder season than we have experienced in recent memory.
Thanks again!