If you take Route 3, consider making a stop in Joseph, OR to see the Wallowa Mountains. It's something most people who live in the PNW don't even see. The Jennings Hotel there is really nice. Road conditions may be icy so look into the weather beforehand.

Also, if taking Route 3, consider taking the slightly longer route along the Columbia River Gorge. Growing up out east, I was blown away by the geography here. Along 2 hours of highway, you're driving through a channel of cataclysmic erosion from the Missoula floods. You'll also see the transition from arid plateau to forested mountains. As you get closer to Portland you'll have a bazillion stops to look at waterfalls such as Multnomah Falls. Hood River is a nice small town to stop in for lunch.

If you take Route 2, you'll go past Steens Mountain. This is sort of a 'hidden' national park, as the locals (all 20 of them who live within 100 miles of the area) protested NPS acquisition in the 90s. There is a cool salt flat you can drive on (Alvord Desert), and the desolate vibe makes it an incredible place to visit. Unfortunately the road to the summit will be closed until late spring, so you won't be able to properly explore this week. Maybe save this one for a future trip, but it's definitely worth seeing. VERY remote...you don't want a flat tire on this route.