I once saw 4 performances in one day. Had a ticket to all three parts of Norman Conquests, which were sold as individual performances. Based on the time, and at the spur of the moment, I decided -- after the second play -- that, instead of dinner, I would see a 90 minute show with Tovah Feldshuh (Irina's Vow???)...the price: I would likely miss 5 minutes of the third Norman Conquests play. I had Sabrett's hot dogs for dinner and will never know how much I missed, but I actually believe that I missed about a minute, based on the stage action the was occurring when I entered.
All in all, a very fun day...and, although Irina's Vow wasn't a great play, I did enjoy it (plus, it was serious...a nice contrast to Norman...