In general I do not recommend leaving the PNW later than mid September for a delivery
south. The last time I sailed from Seattle
to San Diego
in mid October the first 500 miles were miserable (25+ from the South, SE, SW).
A key condsideration is how experienced you and your crew are and how well your boat is set up (and tested) for offshore
passages. I always plan for having 12 to 24 hours of 30 to 40 TWS somewhere between the PNW and Point Conception. (Once out of 8 trips I have motored from Cape Flattery and Cresent City.)
If you asked enough people who have sailed the length of the US West Coast
you may find a 50/50 split between those that prefer to go 40+ miles offshore and those that travel "one foot on the beach". I am with the group that prefers to go offshore for the searoom, deeper water
, and more organized wave trains.
Let me know if you have any follow-up questions.