Hi John. We live in Magnolia, near Discovery Park, and are picking up a Caravel
22FB this week. We just went through locking in storage and it is not easy in the Seattle area. You probably saw that Airstream Adventures is moving to a new location this week with storage facilities. If you are still looking for a space they have availability.
The site the other poster mentioned, which I think is the closest facility to you, is Eastside RV and Boat Storage in Kirkland.
Good luck and hope to see you on the road.