Answer: The prognosis for your plants is probably still pretty good if you are able to overwinter them in an appropriate place.
If the plants are still in containers, you will need to bring them into a sheltered place for the winter such as an unheated garage. Wait to bring them in until late fall when they have gone dormant. Then take them back outside in early spring so they can wake up naturally with the season. The goal of storage is to keep them cold and dormant but above freezing so the soil does not freeze. The maximum temperature would be 40 to 45 degrees, the minimum storage temperature about 32. A little frost will not hurt them in the fall, it will help them go dormant. During storage keep the soil just barely damp, not bone dry.
This hydrangea is unique in that it can bloom on both old and new wood. This means the earliest blooms appear on wood that grew the year before. Later in the season, the blooms form on new growth of the season thus continuing into the fall.
Next year they may not bloom until late summer, if the deer ate them down to the ground, but that is better than nothing.
Next year, give your hydrangeas direct morning sun or very bright dappled light light all day. All day sun or sun all afternoon is not a good location.
If you are having trouble with deer, you will need to protect your plants. A tall fence is the most reliable long term protection but some gardeners report success using repellants. Read the label and be sure to reapply as directed if you go this route.
Good luck with your hydrangeas!
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