Obviously it depends where you are downtown, but, say, from the Alamo to the Alamodome is a little over a mile I'd guess.
BTW, there are still some details to be worked out among the Alamodome people and the Saints re: the tailgate. Two different staffs having to work together on short notice to put together 3 ballgames in a couple of weeks is causing some confusion. A Councilman said today on the radio that they expect an official announcement with final details early next week. I will try to be all over it and let ya'll know what I hear.