Another great game for that was Skyrim. But both of these games are as close to true open world as one can get. And they are single player deals.
Heh - whenever I log into Skyrim, I get so lost and unsure of what to do, I go look at some mammoths then log out again. It's almost too big and open...
Dragon Age Inquisition, despite its many story and gameplay faults, actually found a good balance with open world-like areas combined with hubs. Works well for party based rpgs imho. I think that could work well in a game like this to give the weighty sense of scale and place and add some filler npcs — tho I am now ducking to avoid eggs for saying that.
No I agree with you, DA:I did the immersive huge maps really well, combined with smaller quest maps. I've been re-playing it while waiting for Patch 5 to drop here. Really enjoying it.