I live in Washington State, where the weather is similar to Oregon. November and December are two of the wettest months of the year. Regardless, typically when it rains it drizzles and most of us don't bother to use umbrellas. Expect grey days without sunshine. On the other hand hotels and inns will be much cheaper at this time of the year.

Adelsheim winery does vineyard hikes, we are doing that in August

I would take some time and look up wineries on the Internet. The only reason I say that is there are wineries in Silverton Stayton and also McMinnville area which are at opposite ends of the valley. Both areas have a lot to offer both areas are absolutely adorable in their own way.

The fall weather is usually good in October. Expect cooler days-50-70's and great fall color.The rainy season doesn't really begin until November but's it Oregon so a small umbrella or rain jacket. is always a good idea. WJB

The Allison Inn. isn't a Bed and Bedfreast per se, but it is wonderful place to stay and I would highly recommend it. The location is perfect for exploring the valley. WJB

There are so many great restaurants in Portland it’s hard to choose. It is one of the best “foodie” cities anywhere. As far as staying if you want piece and quiet go to VRBO, lots of places in the valley that are wonderful. If you stay in the city you can easily Uber to many attractions and restaurants. Must visit Voodoo Donuts. Originators of the specialty donuts. ( downtown branch is the original around the corner from the Embassy Suites Hotel). A couple great restaurants=. Little Bird ( French leaning), Jakes Famous Crawfish, best pizza is Apizza Scholls, and for Italian go to Nostrana, When you go to the wineries stop in Dundee at the Red Hills Market and get sandwiches to go and take them to one of the wineries which most have outside tables with great views. You will love Portland. Remember one thing! It is a very cool liberal city😃.

Given that you are planning on spending some time in Portland, and are looking for a base, McMinnville - Dundee might work well for you. Depending on your budget, you may want to a look into the Allison - good place to wind up the day. You are in the rainy season, but for great views you might like a ride around Haag Lake - there is only one rest stop (if it is open) - otherwise.... There is a small grocery store just before you go into the park in case you forgot provisions.

Use Portland as a base. I loved my hotel ( River’s Edge Hotel and Spa) because I was able to enjoy my down time or go into the downtown. The sauna and steam room were great after walking and exploring.

You may suffer slight delays on the coast to McMinnville piece of your trip, but probably nothing more than a slight irritant. You'll remain primarily west of the congested areas (Dundee)