Some pretty good pulls east of Ellensburg until you get to George and maintenance can be questionble at times, as was shown this last winter, when the intersection of I-90 and US395 stayed icy and hard-pack snow covered for a few weeks. It was like they just gave up.
Some of the most catastrophic (read: multiple vehicle) crashes we've had in Washington have been in the canyons and hills between Ellensburg and Vantage. ...and those crashes usually don't happen during winter months.
Take your time, don't get in a hurry and don't let anyone push you. If you're not comfortable running on chains and the chain law is up, park it. In that area, when they say chains required, they mean it.
As for ports, I have no idea. I don't deal with them.