I too would like to know the answer to this. I dug mine up in December after the Nov storm. I moved them into the greenhouse and now they are not looking too good. I washed the roots off for fear of bringing critters into the greenhouse and I don't think they liked that. They are still alive so there may be hope. If I hadn't moved them, I am sure they would have been toast after the last few weeks of nasty weather we have had.

These were fine with the cold, but I think we were warmer than you were in Washington. Last year I transplanted other things before that February cold spell and lost a Philadelphus mexicana 'Rosemary Brown' while the unmoved double philadelphus was ok - the double is supposed to be more tender than the single from what I remember.
The dianella fruited well this summer - I have two, one from Greer and one from Cistus. I was told they are not self fertile. The fruits are a beautiful shade of navy blue.