Actually, it occurred to me today "What if the PCs stayed in Barovia?' What if they moved into Castle Ravenloft and remodeled the place (throw out the dead things, gave it a paint job, added some tasteful throw pillows) and kept a watch on the crypt for the possible return of Strahd (so they surprise him, he doesn't surprise them)? What if they burned the castle down? What if upon the death of Strahd, Shadowfell-Barovia dissolves, dropping everyone into Prime-Material (alternate) Barovia?