Usually one can use a cable to go through the saddle rails and part of the frame (seat stay) to lock the saddle. If the cable is too short to reach through the seat stay, how about let the cable through the rear wheel? Would that be secure, too?

(It seems to me that even if the rear wheel is not locked to the frame or fixed object, it's impossible to remove both the saddle and the rear wheel together without cutting the cable?)