My radio has a Fail-Safe so that if the rx loses signal it can set the throttle to a predetermined position. I cannot decide what is the best throttle position to set for the fail-safe.

-Do I want to set a medium-low throttle setting so that the plane will keep flying as long as possible and I might be able to eventually restore the signal and recover the plane? Assuming the plane is not pointing down when it loses signal or else this would lead to a spectacular crash.
-Do I want to set it to idle speed, so that the plane is going to coming down, but if I restore the signal before it hits the ground I might be able to fly away and land undamaged?
-Do I want it to assume the signal is unlikely to be restored, kill the engine and hope that the crash only destroys the airplane?

What are your thoughts regarding which option is best?