I loved the nines and the awesome roof bar overlooking pioneer square. my website review/trip report is here http://philatravelgirl.com/portland-the-nines-hotel/ with tour posts separate

I did easy 1/2 day bike tour of city, then would suggest a brew tour (concierge team is good at hotel if you call or email ahead). A day at Columbia Gorge is totally worth it to see how gorgeous it is - I did a tour as solo without car.

I didn't get to the Willamette bc tours need two people or don't take solo travelers. Again hotel can arrange it you can visit a few wine bars instead.

The Imperial had a great burger and wonderful blueberry pancakes. Go to voodoo doughnuts early to avoid lines and then compare with blue star donuts. There is a good Italian restaurant in the Hotel Vintage plaza that I liked