Also the pilot in level flight would output 300 watts or so. The engineering values are vaguely similar to some bicycle calculations.
Look for
"Or, to put it in perspective, about 19 minutes to raise a 250 pound bike+rider 1000 feet." and thats at an assumed 300 watts or so output. So your descent at zero power out will be similar, it'll take about fifteen minutes to drop 1000 feet.
http://bicycles.stackexchange.com/questions/13090/extra-powe...
Personally I wouldn't worry about gliding to a landing, I'd be terrified of a wing folding up or shearing off and THEN you drop like a rock. Or indirectly (control system fails in full dive, Vne is like 16 mph so the wings rip off, then you descend much faster....