around 1000-1200 ft/min ..not a smooth touch down , but you'll survive..
If you have this rate on short final, and your flare is decent, this will work out okay, some practice helps. I have done testing with several types airplanes for this characteristic (not an AN-2) to find where "too difficult" begins, and for my experience, it's 1300-1400 FPM. My own airplane power off, fully fine prop has a descent rate round 1600, selecting full coarse on the prop gets that back to 1100, from which a decent power off landing is possible. But, in all cases with airplanes with these power off descent rates, maintaining an unusually steep glide, to a spot which seems abnormally close is vital. Trying to stretch a glide to be like a lighter, more sleek GA type is not going to work.
Not surprising to me, roadside lampposts are designed to break
It's not the security of the lamp post which interests me, but more the noticeable part of the outboard wing leading edge which remains in the "high drag" position after the hit.