Ceanothus is amazingly temperamental - you've got a 50/50 chance of saving it. Prop it up with a really stout post, but without wrenching it. The ground is so wet it should go back to it's original position without a problem. If you can put a support stake on either side while it settles back in. Make sure all the roots are covered by soil again.
My ancient ceanothus appeared to die and OH was about to take the axe to it when I noticed tiny new growths on one of it's old stems. As a result other old stems were removed but that one left and the shrub has made a good recovery. You just can never tell!