I am not sure where you are in zone 6b, but there are several folks in your zone on the New England forum who have posted about Crape Myrtles. If you go to the forum, and enter crape myrtle in the search bar at the top of the page, a drop down menu will let you choose to only look in the New England forum. There are discussions of winter damage in different varieties that you might want to check out, as well as photos.

I'll check it out, but crape are grown all over the place down here in South-central Kansas. They have proven to be very reliable. If a particular cultivar does die to the ground, it comes back the following spring. I had one once that put on 8' of new growth every spring and summer and bloomed profusely every year. Hopi and Tonto are two of the more hardy varieties, and they grow to about the same height and width.

Crape myrtle is not what I would use as a hedge.

Just saying.

Have you ever seen a crape myrtle hedge where you live?