I've heard that the only way to get a sub position without a credential
in OR is for a specific district to hire you, solely for their district.
Which basically means - start networking!
By the way ... there are many programs out there that are under 2 years.
I believe PSU, Lewis & Clark, Willamette U, Concordia, among others offer
11-13 month programs. For most of these, you could conceivably work PT
during the first few months while student teaching is at a minimum (or
mostly at the observation/few hours per week stage), but after that it is
very difficult to work while taking classes, studying, and student
teaching (preparing lessons, grading, etc).