Depending on prevailing winds, you may not go North to the great circle, but go further South to catch the Jet Stream and then approach the Cali coast in a perpendicular fashion...
I've had to divert to a different airport of entry going into the US a couple times, once without any prior warning at all. We plonked into Duluth un-announced instead of making it to Minneapolis, and after a short lecture about keeping CBP in the loop, we were processed without further ado...