I will second the area of the coast around Yachats and Newport. We were just there in September and it was really nice. We stayed at the Oregon House property south of Yachats (
https://theoregonhouse.com) and it was a perfect setup. It has a private beach access that was deserted when we were there and there were plenty of Agates to be found. We also ate at Luna Sea Fish House, and the Halibut and chips was terrific. The tiger prawns were very good as well. We tried to do a whale watching trip out of Depoe Bay, but got cancelled due to fog. We did see a few from one of the ocean overlooks south of town though. The Aquarium in Newport was smaller than some, but a good stop. The Hilltop Cafe in Waldport was the best meal of the trip. I had the teriyaki burger with pineapple on top and it was a top 3 burger for me. My wife had the crab mac and cheese and it was delicious as well.
The area southeast of Eugene along the North Umpqua river was really beautiful as well and way less crowded than the Columbia Gorge and Portland Area. There are a number of waterfall hikes you can do that are fairly easy short hikes and very scenic. We stayed at a glamping resort called Umpqua's Last Resort that was very affordable and very well setup. Queen sized heated bed, heaters and electricity in the tent, good showers setup right near the tent and a firepit with chairs.
The Bend area is also really nice and you can fly into Redmond instead of Portland to get there. We did a cool hike down inside a lava tube out at Newberry National Volcanic Monument, we did a night canoe/starwatching trip out at Elk Lake west of Mt Bachelor with Wanderlust Tours that was fun too. Lots of cool outdoors stuff to do around Bend.
Sunset through the fog from Oregon House

Stairs up from the beach at Oregon House

Umpqua's Last Resort Glamping Tent


Waterfalls along the North Umpqua
