Add my SP11 to the list of affected devices. I am experiencing the same problem - shutdown the machine, close the type cover, leave overnight (or for awhile), reboot - the keyboard is completely unresponsive. Have to physically disconnect and reconnect for the machine to recognize the type cover and render it operational again.
Tried posting on the Surface subreddit but to no avail. Really hoping MS gets the figured out and patched soon - really hate having to disconnect/reconnect my type cover every time I boot my machine.