Consider some of the paniculatas and oakleafs. Although there are some dwarf varities of these now for sale, they generally tend to be large shrubs and should be hardy in your area. Some paniculata examples are Limelight, Quick Fire, Vanilla Strawberry, Pink Diamond, etc. Some oakleaf (a.k.a. quercifolia) examples are Alice and Snowflake; more difficult to find but, with bigger blooms, is Harmony. Many of these get 6' to 10' tall; more if you do not prune. Check them all to see which ones you like and review the estimated size at maturity, a commercial term for "after 10 years". Alice for example can get 10' by 10'. Oakleafs do require soil that drains well as they will get root rot if left in standing water for long periods of time. Limelight gets 6 by 6 but can reach taller heights if left unpruned.

Go to some hydrangea websites and check out their pictures and stats on paniculatas and oakleafs. www.hydrangeas.com, www.hydrangeasplus.com, www.nantuckethydrangea.com

Thanks! Those are some of the ones I'm looking at so good to know I am on the right track. I especially appreciate the websites for more information!