Take this for what it is worth as I have never hunted the coast and don't target divers. Most of the people I know who do, hunt the inland sloughs/tribs and/or wait for the farm fields to flood and hit the puddlers. I would suspect the Columbia River will be the area to concentrate on for divers if you are in that NW corner and want divers - but the bays do get birds and with some study [access, huntable zones, tides etc], can often be hunted.
Of the three you've noted - the redheads probably are the least common; Oregon does get them but not like the Gulf areas in the S/SE. That said, they will still likely pull in all manner of ducks - puddlers and divers. Bufflehead and Bluebills are much more common as far as divers go.
Myself, I keep a few divers in my rigs just for variety here in the valley; plus, the white catches eyes. Depending on how many you have, I'd likely sell off some of the spread and plan on using that money to buy some mallard/wigeon/pintail dekes here to mix with what divers you keep/bring up.
Last point, you probably will not get equal $$'s for diver decoys here as you might in FL should you choose to bring them up but then sell later. Just depends on what game you want to play - there are dedicated diver guys around!
Teal decoys will always work; Oregon gets a pile of them - BUT we do not get many bluewings and we do not have an early teal season [I also have teal dekes in my spread].