zep,
As I said several days ago, it's rather easy to have France win the napoleonic wars. :
"having france win the war (s) is actually quite easy. simply have Nap not make two huge errors: don't invade Portugal/Spain (I consider them basically two sides of the same coin) and don't get sucked into chasing/invading a retreating Russian army. Even with the Peninsular war, France was the master of Europe and the only thing that reversed that was a disasterous invasion of Russia. Without that reversal, how long can Britain hold out?"
Neither side can directly, militarily, beat the other (France can't get to England, England can't threaten France on land). Britain needs surrogate land masses/armies to arm and aid. Take away them, and Britain has a navy, an industrial base, and no way to use either. That was the point of the continental system, which turned out to be somewhat counter productive. a couple tweaks here or there, might make it work (such as ignoring Portugal, which really wasn't a threat, or not getting sucked into Trafalgar). France very well may have been able to simply ignore Britain militarily and not implemented the continental system. Britain only had a war to prosecute because France gave them one.