Props to you, and apologies for thunder-stealin' good sir.
All:
If France wins enough to impose terms, which of these old territorial borders is France more likely to claim from the German states if it wins, a relatively modest increase to get the borders of 1814 (in orange) or a much more dramatic increase to get the border of 1801 (in blue)?
How well would either of these impositions be received Europe-wide or in Britain?
Yet a third option, perhaps more sensitive to the divisions between German states, might involve French annexation of Prussian Rheinprovinz only, leaving Bavarian Palatinate alone, while resurrecting all the states liquidated by Bismarck in 1866 like Hanover, Electoral Hesse, Lauenberg, etc.
A fourth option might be France being restrained and taking no territory for itself, but resurrecting all the states liquidated Bismarck in 1866, and then brokering an exchange of the Rhineland-Westphalia to the Wettin Dynasty of the Kingdom of Saxony, to get the Prussians off France's border, compensate the Wettins with a larger Kingdom, and keep the Prussians and Austrians in each other's faces.