A couple other places to call:
Highland Park Improvement Club
http://www.hpic1919.org
West Seattle Christian Center – not sure if Ginomai or the new event center has room but you could ask
http://www.westseattlechristian.org
So many churches have meeting rooms or other spaces, if you haven’t tried them all yet.
Also worth asking – Kenyon Hall
http://www.kenyonhall.org
Hope that helps for starters, and that others have ideas to chime in … Good luck! Is this a new policy, or they just needed the space for somebody else?