Last week coming back from Sausalito to Eugene took me almost 10 hrs (560 miles IIRC) during the day and with good conditions.
Keep an eye on the weather and be flexible with your plans, if the wx is bad expect delays in the mountain passes (Siskiyuo and Sexton).
Talk with these guys http://advrider.com/forums/showthread.php?t=412129
as they have an impressive knowledge of the roads around Eugene (and the watering holes)
I will be down in Arnold CA for the holidays, otherwise; Mi casa es tu casa... but if in a pinch you need something in Eugene, let me know and I may be able to help.