Based on what I've seen and heard about hydrangeas in the Pacific Northwest, you should have nothing to worry about. For some reason, they bloom a little later there but they also bloom a lot better/easier there. No need to winter protect it or prune it. If you like, give it a little evenly balanced slow release fertilizer, (now is a good time) water it now and then and sit back and watch the show.....yg

If it's very small, it may also be very young and establishing itself and it root system...but then again you may have flowers this year. I can see the beginning flower buds on most of my hydrangeas, but I'm so close to the ocean, both winters and summers are more mild than just a few miles inland.

Your sun/bright shade sounds good, and they don't need protection in winter in Western Washington. They do need regular water during our dry months (late summer, early fall). I never fertilize mine, but I top dress shrub beds with compost each Spring.