Specifically, after a French defeat in World War I.
As much as I would have liked that, the revolutionary left was far more powerful and influential in France (still is kind of). Unfortunately, a royal restoration of any kind in that time period looks next to impossible: A far more likely scenario would have been a red revolution similar to OTL's Russia.
If you've heard of the Hearts of Iron II mod "Kaiserreich" where Germany wins the Great War is an example of one scenario such as this.