Break Bretonia into 3: Gallic puppet focused in Leeds, and occupying civilian centers in New London while the Gallics command the military structures. A Bretonian Government in Exile in Alberta coordinating with Liberty (still in a war or in a Cold War status with Gallia) to restore the House. A Bretonian refugee community in the Omegas, supported by the Commies and running resistance efforts in Cambridge alongside the Mollys or something.
That is, after the end of a campaign that makes Bretonia independent existence impossible to maintain, but so costly to Gallia that it seeks a truce from it's position of power, to recover and reorganize for the time being.