Hello there. It's a pretty straight shot and probably a nice downhill run most of the time. You would likely have a broad reach, beam reach, or be on a run. So if your boat does 4 kts on a broad reach or run... let's see...
Coos Bay OR to Aberdeen WA (in the back bay part of Gray's Harbor) is 244 nm per https://www.nauticalcharts.noaa.gov/.../distances.pdf
So, that would be 61 hours underway more-or-less.
If you planned to stop along the way, you might go in at the Columbia River, Newport OR, and well...a few other spots and it might take a tad longer.
Hope this info is helpful to you!