Hydrangea

Question

Will a hydrangea survive in a north facing garden in a large tub.

Answer 1

In a container, figure the hardy zone drops down one. So if your in zone 5, a container is exposed to zone 4 conditions.
You may want to move the container to a garage or shed after it has gone dormant.

https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/hydrangea-container-care.htm
https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/hydrangea-winter-care-how-to-protect-hydrangeas-from-winter-cold-and-wind.htm