I did a bunch of coke last night/this morning and I have a deviated septum surgery in 12 hours! Will they cancel the surgery?

Yes. You are definitely at great risk of either an anesthesia or surgical complication. You really need to discuss with your surgeon and let them know what's happened. They will likely reschedule your procedure for a few months in the future when you've abstained from any cocaine use. Stephen Weber MD, FACSDenver Facial Plastic Surgeon

You run the risk of serious cardiovascular complications as well as total collapse of the septum with a deformity that cannot easily be reconstructed. You need to call and cancel the surgery. The excess alcohol intake can also cause extensive bleeding necessitating the possibility of blood transfusions and pulmonary damage from aspiration. 

You should be very worried, as should your surgeon and anesthesiologist, if you honestly tell them about this.  Aside from cocaine's effect on the nasal septum, it causes potentially deadly complications with cardiac arrhythmias during anesthesia and surgery.  You should definitely cancel this surgery util you are clean.