It really isn't that hard to draw a 5-1 map while leaving all of Eastern Oregon intact. The key is to draw a Eugene-Ashland district and then split the Portland metro 4 ways (basically NW Portland+Beaverton+Hillsboro+NW Coast, SW Portland+Tigard/Tualitan+Yamhill+Polk+Benton+Lincoln, NW Portland+Gresham, and Inner SE Portland+Clackamas+Marion+Linn)
True, the issue is that the Eugene-Ashland district needs to take in a lot of conservative territory, so it's really difficult to shore up without yanking too much liberal territory from the new district and the 5th or reaching into the Bend cookiejar.
It's possible if you carefully carve up Jackson and Josephine. The 5 Dem districts in this map should all be Clinton+5 or more.
On that map the 5th (teal) is about D+2 and Clinton+3, while the 3rd (red) has an Even PVI and is only Clinton+1. Also the eastern R pack is certainly oversized for pop.