Apologies if this has been asked before. I tried the search function, but with my luck it didn't work, of course.
I think everyone agrees that it was pretty difficult if not impossible for the 2nd Empire to defeat Prussia and her allies in the war, certainly not without a sufficiently early POD.
However, would it have been possible for the two sides to fight to a standstill? I would define a draw like this, for starters:
1) Germany still becomes unified under the leadership of Prussia,
2) France doesn't suffer major territorial losses,
3) No siege of Paris.
Naturally, crowning King Wilhelm as German Emperor in Versailles wouldn't happen here. Is this possible, or would this also be hard? For starters, I think it would help the French if Napoleon III stayed in Paris instead of going to the front in an attempt to imitate his uncle.