Portland is surrounded by the beautiful ocean and the mountains, plus there are so many get restaurants and shops in the city that you would surely appreciate staying a few more days to explore the NW.
Here are some suggestions:
Get lost in Powell’s books, the largest new and used bookstore in the world.
Go see the symphony or a concert at the Arlene Schnitzer Hall
Schedule a walking tour to see the Best of Portland, Epicurean Excursion, Flavor Street (food cart tour) or the Chocolate Decadence tour.
Best Pizza: Ken’s Artisan Pizza
French: Le Pigoen
Seafood: Woodsman Tavern
Brunch: Clyde Commons
Happy Hour: Portland City Grill (best view of the city)
If you rent a car:
Visit one of the 32 wineries near Portland.
The coast is only a 1.5 hour drive. Cannon Beach has great restaurants and shops.