What if the revolutionaries took control of France 3 weeks before the Franco-Prussian War? Say the guy flees to Austria without a fight, taking his personal belongings, and the Bonapartists are left without their leader. Then France declares war of Prussia and the battles up to Sedan happen just as they did in OTL, except with 1/3 of the German casualties (land gains the same, French casualties the same)?
Would Napoleon III even want to come back?
Also, does history even change all that much? (After this point, we are getting rid of the extra boost to the Prussian military effectiveness)