My guess is that they would have simply shown another game. However, that has never been an issue in Nashville, as "tight'uns" games have always sold out. Wouldn't have been an issue before 1973 here, because we did not have a team here back then.
I am curious, however, as to what might have been shown in Memphis in 1997 when the Tennessee Oilers (as they were briefly known at the time) were playing their games at the Liberty Bowl while Nissan Stadium (as it is known now) was being built. Oilers games never sold out in the bluff city while they were playing there (save for possibly the Steelers game), so Bud Adams moved the team to Nashville for the '98 season, and they played at Dudley Field at Vanderbilt. I can only guess that the paltry showing at games in Memphis, especially when compared to the fans who showed up for the Steelers game, was an embarrassment to Adams, so rather than play another season at Memphis, he moved them to Nashville a year ahead of time.