I would imagine their insurance would replace the vehicle. Smoke like that permeates everything, it is probably in the insulation and leather and carpets and headliner and every other porous material.
The fact that they detailed it the next day without showing you the car leads me to believe it was in pretty rough shape - wouldn't be surprised if there was heat damage as well if it was only a couple of bays away.
Just watch this car fire, imagine that smoke inside of a building and what it would do to a car!