M.P.
All states are mandated by Federal law to provide special service for children who would have difficulty learning if they didn't receive extra help. Their services cost nothing financially.
Have you talked with Multnomah County Educationas Services? This is the office that co-ordinates and provides numerous services. I don't know how Washington State could provide any better services. This service is mandated by federal law. They are funded with Federal moneys. IT is the same in both Washington and Oregon.
My grandson is in a special needs kindergarten and receives speech therapy, occupational therapy, and something else that I don't remember. He has an IEP (individual education plan.) His mother pays nothing for this program.
My grandson is also covered by Kaiser Permanente Insurance and he's been able to receive speech therapy with only a co-payment of $20.
Before you take the drastic step of moving research what is available in Oregon thru the Multnomah County Educational Service Distric.