I usually try to roleplay my conquest a bit. Usually by the point that I've completed my goals, there's nothing stopping me from continuing to the ends of the earth, but it doesn't really feel right to do so.

Its nothing like say MTW 2, where I had trouble expanding past Africa as Spain because the Mongols had multiple full stacks waiting for any armies I shipped all the way across the world, or when I barely won as the Russians because transporting modern armies all the way to the front lines took years. Its easy in ETW so I limit myself.