What if Napoleon II lived?

I would expect that he would end up in the Austrian army and likely end up married to some Habsburg cousin of his. He is unlikely to permitted to go to France and his existence will likely keep Napoleon III from coming into power in France. If he has talent as a general he will likely be do well in wars in Italy (and he will likely do well in Italy as long as he‘s not incompetent) and without Nappy III in charge of France, that will likely be enough for a Austrian victory in Italy. All in all his line of the House of Bonaparte will likely more or less end up ad part of the extended Habsburg family, and his sons or grandsons may be offered minor crowns as proxies of Vienna.