Kelowna to newport oregon

The Summas route is divided hwy all the way to Corvallis except for that bit in northern Washington. Beware that this weekend there's some lane closures on I5 in Olympia (though last weekend traffic was light and there's weren't any backups). I205 works as a Portland bypass with this route as well. In the Seattle area, a freeway bypass through Bellvue and Puyallup may save a bit of time.

The US97 route is mostly 2 lane. Google Maps suggests US17 and 28 to bypass the mountainous part between Wenatchee and Ellensburg.

Unfortunately we will be booking it (at a safe speed of course) as we only have a week this trip. So will have to worry about scenery when we get to the coast. More concerned about the quickest and least congested route. I'm ok with the extra 1.5h if it means fewer crazy drivers. That 205 around portland looks good.

Sounds great to me! I just did the Dalles to Newport portion a couple months ago as part of my summer trip. But I've been on the rest of the route sometime too. Just before Portland, you might want to take 205 down to I-5 to avoid driving through central Portland.

Come on down 97 to Redmond. Head west thru Sisters to Salem on 22 and on to the coast. If you really want a nice drive take 99W south and pick up 20 at Corvallis. This way you avoid the Portlans mess and avoid all most all freeway hassles.
BTW there are two ways south. 97 all the was or head east toward Grand Coulee. Which IMHO is a better drive.