Then again, why would I surrender to a superior foe if they haven't found me yet? Who knows, I may find a dragon somewhere and make a comeback...
I know it's not in the game (yet), but really; why surrender when your enemy doesn't even have your location?
I've seen two sides of this. I was able to make Tarth surrender without finding their last city or sovereign, but I haven't been able to make Gilden surrender, even though they are much less powerful than Tarth was.