I live in PDX. Are you renting a 4x4? Check for permits, but you're timing is good for fall at elevation and maybe some first snow. Thinking aspens along the hike to No Name Lake/Bend glacier on Broken Top.
Gorge: Pick any hike you want to a waterfall. Beacon Rock is also unique (WA) side. Thunder Island in Cascade Locks. Pfriem, Ferment and Full Sail in Hood River.
Hood: Larches will be close to turning. Maybe some new snow. Hit a few of the orchards/vineyards on the Hood River Fruit Loop on your way up. Lost Lake is our favorite. Mirror and Trillium are also fun.
Heading south: Trail of Ten Waterfalls is a must. If you have a 4x4 or willing to hump it, tack on Abiqua Falls and then grab a brew at the Abbey that owns it in Mt. Angel. This is also near the wine AVAs.
Bend: I'd skip Smith. Cascade Lake Scenic Byway. Hop off the pavement and bounce the lakes via fire road. Camp wherever you want! Devils Lake is a unique one! I was just at Todd with my 3 year old last weekend. Tumalo falls in Deschutes National Forest. Bend Brewing on the Deschutes. Crux. Deschutes. So many breweries.
Crater Nat.
On the coast, our favorite by far is Oswald/Falcon/Short Sand/Smugglers cove. It's a short hike, through old, old growth massive coastal red and spruce to a secluded cove. Bonus waterfall on the beach. Out of time, so much more - have fun!
Edit: Oh, we also always recommend Sugarpine right off the plane. 20 minutes from PDX. On the Sandy and a great first flavor of the Gorge:
https://sugarpinedrivein.com/.