without any fairness, i used to ride all winter long in the the northeast; me and a couple of other masochist types. throw on the Nokians and bundle up properly (disc brakes ignore the ice and snow, with only a little more squeal when it gets below 10°F or so)---we really enjoyed it. plus, you don't have to pay for a lift ticket or drive anywhere to have additional fun. like all my bicycling activities: you walk out the door of your home, and you're already having fun.
of course, this really only applies to hard-pack or ice; deep powder (>12") is mostly no fun, even if it is one hell of a workout; usually because there's even more soft-pack and ice ruts under the deep powder.
i live in the willamette valley, too; except for the onslaught of allergies and the 9-month solar disappearance, it's made me soft.