Hydrangea paniculata 'Grandiflora', a/k/a PG, does very well in Zone 7, but this species reqires several hours of sunlight to bloom well. Can be grown in full sun. Does not bloom at all in total dense shade. It is also the type that blooms in late summer and on new wood, so it can be pruned in late winter and early spring.
Give them plenty of room, as they can become quite large.
Regular watering and fertilization can increase flower size.
With their thick woody stems, young Hydrangea paniculata plants can be pruned to develop into a tree form.
Rooting is best accomplished from softwood cuttings in mid- to late summer. Can also be propagated by layering.
An easy Hydrangeas to grow and once established, is drought tolerant.
Rb

Oh I really love this tree. We had them in our NJ. garden and you'd see spectacular ones all around the area. They can be quite impressive!
I haven't seen any in my travels here (except for a one little sad one growing in the shade).
Does anyone grow them?