Answer: According to your zip code you are gardening in zone 5 A which is the coldest part of zone 5. In that area these bushes may be root hardy but they would not be bud hardy. This is a problem because they bloom on old wood that grew the previous year. If the buds or stems are winter damaged due to cold, you will lose the flower buds for the coming season. For the same reason, pruning in fall or spring, or pruning to remove winter damaged stems, removes flowering wood.
You might be able to protect it during the winter by providing a windbreak and also wrapping it in a cylinder of wire mesh stuffed with dry straw or oak leaves and then covered loosely with a tarp to keep it dry. But, that is a big maybe.
Instead, you might want to consider trying one of the newer vartieties that are able to bloom on both old and new wood such as Endless Summer. These will still bloom even if killed back to the ground every winter. If you try one, be sure to plant it in a protected area with shelter from winter winds.
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