In Stargate SG-1 the Asgard died because they were losing the war with the replicators and the fact that they were clones and there bodies were failing them and they found no way to stop it plus many other reasons!
But in Stargate SG-1 they had found many devices and technologies including the ability to travel between parallel universes. Why not use this device to see if any of the Asgards in the parallel universes had found a cure to their problem.
Additionally, they were a part of four great races that were just as smart or if not smarter than they were. I know the ancients had either died or Asended and we're unable to help, but what about the Nox or Furlings? They could have helped them with the replicators or to help they stop the cloning process.
Also, why not put most of their people in stasis pods while others protect them and hide whilst they figure out away to survive?
Finally they were cleary able to rebuild their colony after they left the Ida galaxy, why not do it again -possibly to the Pegasus galaxy? They could even go to Atlantis as the ancients had found a way to defeat the replicators and they would be able to use the knowledge of the ancients as they were far superior in technology and that they were much smarter.
It just seems like they had a lot of options to somehow survive. This just bothers me because they were my favourite characters and I just didn't get enough of them. Hahaa