It sounds like you are looking for something NOT in the DC area, but just in case or perhaps as a temporary solution, have you looked at Nora in Silver Spring? My DC is in his second year there, and I know they have lots of kids with similar profiles - ADHD/ASD/LDs but on a college track, mental heath challenges, complex medical needs, etc. They run a rolling admissions cycle and will take new students anytime as long as they have space. They are not a special needs school in that they don't provide those services directly, but in our experience, they understand these kids and are very willing to do whatever it takes to work with kids and families to help them heal and thrive. It has been quite literally a lifesaver for us.