Originally Posted by
Skyblade
It's not ten years though. Ten years passed since Braska took down Sin, yes, but we never get a time for how long it takes Sin to come back.
FFX-2, however, would suggest that it's actually less than two years. If it was more than that, the majority of Spira wouldn't be likely to accept the whole "Sin never comes back" thing, since the time limit hadn't gone by yet.
So you probably have between a year, to a year and a half. And the journey is across most of Spira, it isn't safe, and it isn't fast. People might try to complete it, but some will die, plenty won't want to be summoners in the first place, and others just won't finish in time.