I moved away from my Pennsylvania farm and therefore from my Savannah roses two years ago, so I don't have any recent comments to add. But Savannah was one of my favorites, if not my top favorite in the three years I grew her.
I learned about Savannah in Peter Kukielski's book, "Roses Without Chemicals" in which he mentions that someone suggested that he grow Savanah in the Peggy Rockefeller Rose Garden (in the New York Botanical Garden). He did so and found that it did very well in New York too.
I am so glad she is doing well in WA too.
