Do you think it’s possible that Vroengard could be re-build at some point in the future once the Riders have increased in number?

After Eragon defeated Galbatorix it’s said that him and the elves used there magic to purge Urubean of the magical radiation left behind by Galbatorix’s explosion

So it’s seems feasible to me that Eragon could do the same to Vroengard. Of course Eragon would need help from the Eldunari, the other Riders that will eventually pop up, and possibly the elves. But they could theoretically make Vroengard habitable against and rebuild Doru Areaba.

The Dragons will need a place to stay when they return to Alagasia. So since Vroengard is so far removed from the lands of the other races it’s would be a smart move to repair the island.

And also that way the Riders will have a headcounters to operate from while they are in Alagasia so that they don’t have to go all the way to Mount Arngor