Recently, I was in the same boat as you... checked for weeks and weeks which felt like round the clock. Then finally, I used touringplans free reservation finder for the first time ever. After a few days I received a text from them around 6am that there was one available and was able to grab it. Worth a shot. Like some PP’s just mentioned, often same day or day before Oga’s ADRs show up with people last minute cancelling.