i would recommend a disaster occuring in other regions of tamriel, as in earthquakes, meteors? invading armies who have left waste to cities (would have good quests linking to this scenario), mehrune dagon returns (more possible quests, although too much relation to oblivion, i do not recommend this as much), stormcloaks retreat to morrowind/cyrodiil etc. this would decrease the amount of work, and help get more quests into the game, it would indeed have less cities, but, with enough effort put into the quests and the story instead of some cities/towns, you would have a better opportunity to make the scenarios that i have jotted down for you better and link to the story line of the mod. Hope this helps
