Cyrodiil was pretty flat and not very interesting in terms of topography. Basically, it reminded me of Solsthiem. Skyrim seems more like Vvardenfell, craggy, mountainous and overall, just more interesting in terms of level design possibility.
There have been hints at a Daggerfall expansion or DLC for Skyrim.
Todd Howard
"I'd like to see the city of Daggerfall redone, or Sentinel. Daggerfall should be on a giant bluff, overlooking the Iliac Bay, and we just couldn't pull it off well then."
I'd be open to that, if it was done Mournhold style. I think redoing all of High-rock would be a disservice to the Daggerfall game.