Some chat going on here on constant attitude vs variable flare technique. Both are valid techniques, unfortunately they both rely on visual references to fly them.
Advantage of the constant attitude at night vs the variable flare is that it all happens a lot lower height, ergo you might stand a chance of seeing something to enable you to cushion landing. The drawback is that you will probably have a higher run on than from a variable flare.
Either way an engine off at night with no electro optics would be very exciting. (Final word on the constant attitude thing, don't go too slow or it will all go very wrong)!
