Ok let's try. Everything is possible. Nivelle should have learned Brussilov's lessons: short and massive artillery barrage, infiltrate shock troops, launch attacks against all sectors and finally deploy your reserves to exploit the breakthroght, when one of your attacks breach the enemy lines. In 1917, Hutier learned Brussilov's lesson and he won Riga (in september). Nivelle didn't learn the lesson and he lost Chemin des Dames (in april, just 10 months after Brussilov's offensive).
Tanks are out of this game, because in 1917, French had only Shneider Ca1, the worst machine of WW1. And so, we can rely only in shock troops.
- January-April 1917: French Army begin to train new infantry units (shock troops)
- February-March 1917: Germans execute Operation Alberich and evacuate the salient.
- 17 april: after a short and massive artillery barrage, French Northern Army Group and French Reserve Army Group attack the Siegfridstellung from St. Quentin to Rheims; shock troops inflitrate enemy lines before dawn and cross German defences near St. Quentin, La Fere and Vailly; French infantry breach the lines in those three points
- 18 april: French Norther Army Group exploits the success in St. Quentin; French Reserve Army Group exploits the success in Vailly-Cerny sector.
- 19 april: a two pronged French maneuver converges on Vervins; Siegfriedstellung defences are compromised, German OHL has to order a general retreat
- Aftermath: I don't think this victory could determine the end of the war. Germans could stop it as British stopped Operation Michael of 1918. But it could inflict heavy losses to Germans and avoid French mutinies.