I have a cryptic note in my 'good guts' book for the 300/400 that says 'can do single engine autoland (dual channel) at flap 15 in emergency provided APU used as second generator.'
Can't remember actually trying it in the simulator, but it would seem reasonable if the visibility was down and you had lost an engine and had a good reason for not diverting to your takeoff alternate. One could write up how you did it and why you did it in the ensuing incident report and no-one would notice or care, methinks, as once it is an emergency the gloves are off - even Boeing allows that if I read the preface to the manual correctly.