I think it is realitic for this GE and the number of games played. I just thought it would be unrealistic for a real life situation, but then I did not take into account the quandary that is the unpredictability of real life.
By doing a bit of resarch I found a 7 OT DI game on record.
http://wiki.answers.com/Q/What_game_holds_the_record_for_the_most_overtimes_in_NCAA_men's_basketball_Division_1-A_history
Sorry I do not know how to do direct links yet.