Preziosa is hardy only to Zone 6 and will require winter protection if you wish to have blooms and protect the stems. On a mild year, you may get by with some blooms in some stems but on a very cold winter, all stems could dry out and then all growth would come from the crown (there would be no blooms).

My experience:

I have two of them in different parts of my yard and they bloom like crazy no matter how cold it gets in the winter or what kind of spring frosts I get. One of them is under a White Pine canopy, and the other is out in practically full sun with no protection at all. I have never covered them or done anything special to them at all.

All of my Hydrangeas (Macros and Serratas) have somewhat blackened leaf tips this year, but there is green growth emerging from under the black, so I think they'll be fine.

But this year has been weird, so we'll see.