I hate to split hairs, but either can auto-rotate and either could be survivable after "simple" engine failures.
However, the Chinook cousin I was familiar with in 'Nam fell like a rock 'cause the engines quit when a round exploded a transmission and the rotors failed to autorotate for some mechanical reason.
If, IF you could find one pilot with equal skills in both ships (forget the one vs two engine Bell problem) I have no idea which he/she would choose.
Sorry.
P.S. I once flew often with a Hughes 300 pilot who could autorotate into a landing smoother than kissing a babies cheek. In a OH-6A he was a deadweight P.O.S. Which leads me to believe that pilot skills would make more of a difference than airframe.
Sorry I can't give you a better answer, but us fixed wing pukes have been known to be brick-dumb about fling wings.
Fixed wings are for those pilots who can't do more than one thing at a time.
" Fixed wings are for those pilots who can't do more than one thing at a time."
With that statement, I assume that you aren't instrument rated flying single pilot.