It's been a while since I read The Provinces of Tamriel, but Summerset Isle, I think, could be small enough for an expansion. I assume Summerset Isle is about the same size as Solsthiem or The Shivering Isles. But Bethesda will most likely save using Summerset Isle until they make a game based solely in Summerset Isle.
Actually if the map of Tamriel is to be believed, then Summerset Isles is almost the same size as Skyrim. Sadly not expansion material, perhaps its own game, but not an expansion.
yeah i am. if you honestly think that a summerset isle full game would be good. Then you need to rethink why you play elder scrolls games.
I think it is you who needs to rethink your attachment to the game. Summerset Isles is an archipelago that we know next to nothing of... Except that it is dominated by magic, is believed to have been occupied by the Sload and they still use their necromancy in attacks on the Isles, the closest province to the Maormer and the believed landing point of the Aldmer.
You're right, Bethesda could never do something with any of those.