I can't imagine that the Cardassians could recover. They are presented as having inferior tech (although the Dominion likely gave them the information needed to put them at parity with the Feds), far fewer resources than other empires (thus why Ocett was interested in the possibility of a limitless source of energy, and why they needed slave labor and to mine foreign worlds). Their only strength was their tactical prowess. It seems unlikely that with their resources even further diminished, and the fact that at least a portion of the Union is now at the mercy of the Klingons and the Romulans paints a bleak picture. Just as well that they're done.