From what I've read MT did offer (or she was courted by the Poles) to marry a daughter to the king of Poland (this would be Maria Elisabeth). And her eldest son was betrothed at varying points to Maria I of Portugal's youngest sister (a match to Maria was never considered), the last time after Josef's second wife died. The ship to carry Benedita to the Netherlands was built and everything when Josef declared that he wouldn't marry again.
As to Poland, Stanislas looked at Benedita or at Maria Elisabeth, but Ekaterina II meddled and blocked both marriages. The Saxon crown prince was betrothed to Marie Zéphyrine de France (eldest sister of Louis XVI) and then to Mme Clothilde, but eventually married a princess of Zweibrucken.
Louise-Élisabeth de France, duchess of Parma was key in arranging a match between Josef and Isabella of Parma, mostly cause she was trying to secure the Belgic crown for her husband. Her other ambition was for her younger (and favourite) daughter, Maria Luisa, to wed the duc de Bourgogne. She and her sister-in-law, Maria Amalie, came into conflict about Isabella's betrothal to Josef, since the latter wanted Josef to marry one of her daughters (Maria José or Maria Luisa); and she (Amalie) considered one of her daughters a better match for Bourgogne since they were royal, rather than the daughters of a mere duke.
And the dauphine also jumped on the bandwagon. She was as Austrophobe as any of the Mesdames, and had tried to arrange a double match with Poland - Bourgogne to Amalie (OTL Pfalzgräfin of Zweibrucken) and Zéphyrine/Clothilde to Friedrich August III - but both came to nothing.
In a way, without a diplomatic revolution, I could see the Bourbons turning into a hot-mess of inbreeding a century earlier. The Habsburgs might make some more marriages into the German ruling families - Welf (and it's Italian branch of d'Este), Wettin, Wittelsbach (maybe Amalie duchess of Parma gets to marry her sweetheart) etc, like Leopold II's sons did (Württemberg,Habsburg-d'Este, Wittelsbach, Nassau, Holstein/Romanov, Askanier, and contemplated matches with Baden (for Franz II and the duke of Teschen) and Prussia (for Franz Josef)).