Does anyone know whether the Great House councils the player interacts with in the game are leadership for each House throughout the entirety of Morrowind, or were these merely regional councils for Vvardenfell? I remember that the Redoran moved their Council to Vvardenfell under the leadership of Venim to take part in the land grab when the island was open, but I also feel as though there was dialogue that indicated that the Vvardenfell Great House councils were only localized councils.
Also, piggybacking on my primary question, is the Grand Council in Castle Ebonheart the Grand Council for Morrowind, or is this council only concerned with the local affairs of Vvardenfell?