I had been working on a very large city mod complete with quests, a new race, and an entire main story mystery for the player to solve (main story for my mod I mean). It took place in a behemoth citadel I made using as the base area one of the Stronghold platforms that came with the game scaled up to double size. That's huge in Vvardenfell's landscape, and there was no easy way for me to get away with it without interfering with dozens of other people's mods.
And yeah, I know firsthand how much work this stuff requires. I worked solo on all my mods for about 3 years, and only the smaller ones ever got finished. It's really hard to get large projects done because people lose interest and life isn't static. Still, I was rather hoping that a finished landmass had been completed for modders to play around in. That's why I got so excited when I saw the screenshots and I hadn't even been aware such a thing had been worked on.

But, I just try and pretend that this isn't really how the lands would be. I think of it in the style of Final Fantasy VII, where when you were in the "overworld" all the cities were little objects placed on the map and the world map was scaled down so small for ease of getting around. But when you bumped into the city objects, you then got teleported into a huge city map.
I actually started work on a mod similar to this for Morrowind. Since the land was so scaled down, I thought: Let's keep cities in the world smaller and completely walled off, and when the player enters we'll teleport them into another cell where the real city is. This would let me make the cities much larger and believable without wasting the limited exterior cells. The problem I ran into was that, at the time, you couldn't make interior cells look like exterior cells. At least not with creating fake land meshes and sky. I believe it was Tribunal that first introduced "interior exterior" cells, but even then you still needed to have meshes for the terrain. I ended up scrapping it because of those obstacles, but also because I wasn't sure if players would like the idea of separate city cells since they were all open cities in Morrowind. It's ironic that Bethesda themselves ended up choosing this method in later games.