I would love for some future TES game to have full-scale Tamriel or even Nirn. Imagine finding Whiterun and it looks like this:
faction quests that are actually very long so it would take 500 hours to finish main quest alone for example. Sounds overkill but that would really be an epic long time adventure and imagine the satisfaction of saying "Yay, I'm the fucking master of Dark Brotherhood, I remember how I just started their quests last summer". I do aknowledge that this is extreme and I don't know if it would actually work as a game, but dreaming never hurt anybody.
Hey, 30 years ago current tech in games was only a dream too.