I live in Washington State too, up in Bonney Lake. I don't have heat or light in my coop, but the girls are still laying the same amount of eggs. They are in the coop by 5pm & I don't let them out until 8:30 am when I get home frrom work.
I hate the cold, they don't care. I have a tarp over their run for rain & they have to stay in the run while I sleep, but my mastiff is a Double Agent & will push their pen open & let them run free. In exchange, they let her eat what she wants from their selection of breakfast. Conspiracy!
I move the tractor closer to the house for wind & below freezing & I have an old rug I thrrow over the top, but they seem ok. I am keeping an eye out for anything unusual. A lot of people ask me if I bring them in the house when it gets really cold. I just tell them no, I have knitted sweaters & socks for them! 
We are almost neighbors, I live on the outskirts of Orting!mine put themselves in the coop by 4:30 PM, if I don't go out sooner to bring in the water etc., then out at 7:00(daybreak here) sometimes there are several eggs waiting and other days they lay later. The other day I only got 5 eggs, that was a first since last Summer once they had all started laying. Back up to 9 eggs today. can't quite figure out why the decline. Must have been upset for some reason.

















30 below! I felt bad for the girls when it was 2 the other day! Hope your girls are OK
Another storm is moving through the Aleutians today, and by tomorrow and Wednesday...well... the forecast is for above freezing.
Which means I'll be cleaning coops, if that happens... 

Hey there Alaskans! Here in Illinois this week we've been 40 degrees!
It's like we flew south for the winter, but without the flying! Wish you had some of this easy winter.