That feeling…when you want to go to bed but that CNC in your room is still not finished… 
the feeling is mutual my friend but with my 3d printer… waiting for it to finish…
I had 3d printers run through the night serveral times but I find a CNC machine too dangerous to do the same without me at least listening for strange sounds and being able to jump to the e-stop button.
why don’t you add camera and a raspberry pi to to watch and listen for any abnormalities and if any problems occurs stop it or make an alarm
One more thing to fail.
hmmmm