If you have Care Oregon, you may possibly be able to see Dr. Ed Hoffman Smith (at the Natural Childbirth & Family Clinic) in NE Portland.
You might also try Dr. Egelseer at Oregon Pediatrics. Their practice is very large, and I'm pretty sure when we were there last, I overheard an OHP mama at the window. Just see ONLY Dr. Egelseer there. She has never made any mention of my two non-vaxed kids, although our family doesn't do well-child exams, so we've only seen her for actual medical stuff (food allergies, skin rash, ear infections, etc). But she is very friendly, very supportive of extended breastfeeding, and our non-vax status has never been an issue with her. Other physicians in the same practice are not so nice, just to forewarn you, so be sure that you are seeing her, and not just making a general appointment.
Many of the really great pediatricians in Portland aren't accepting new patients right now, OHP or no, which is a real bummer.