During the Battle of Terra, the Concordia took significant damage (principally from three torpedo hits IIRC), and as a result was subsequently assigned to “safe sector” patrols. In the Armada manual, she is described as “growing rather rickety after years of abuse”. (And keep in mind that her PTC presumably no longer worked or was simply not used.) In a rearguard action in the Vespus System, over Vespus, she was attacked and effectively destroyed. A survey crew, which included Blair, found the “broken hull lying half-submerged in the waters off the Mistral Coast”, the scene shown at the beginning of WC3.
Not sure why you’re asking the hypothetical on ramming, but I doubt that the ship, despite its size, would come out unscathed.