History's solution for this, almost invariably, is both simple and guaranteed effective. The leftover men are called an army, and they either die in combat or conquer foreign lands, where they can take -- by force, usually -- the stock of available women after killing the menfolk in battle. In either case, the imbalance is corrected.
That's the real "leftover" story in China: if those men aren't to be an army, then what are they to be?
http://www.chinawhisper.com/6-pictures-of-chinese-farmers-an...
http://rbth.asia/society/2013/05/25/the_key_to_a_happy_russo...
Or they conquer their own land, i.e. a revolution.
Maybe, but that doesn't solve the problem. They're still single and would rather not be. Something else still has to give. A very long civil war might do it, if that's what you're suggesting.
Plus migration and things too...