Bob, 5 hours in decent weather, but you can get a lot of rain on the way in November.
One note to keep in mind - it sometimes snows in the coast range (which you need to traverse on the way to 101). There are times when you legally need chains on your car up there - I personally remember a couple of times US26 was "chains required" around Thanksgiving.
So, keep your eyes on the road conditions, and adjust as you see fit. OR126 from Eugene is usually your best bet over in bad weather.