There's a somewhat groovy equation to predict enthusiasm for the entire season, day by day. I found it on these forums a few years back, so I'm happy to share it here as well.
=5+(E-5)*0.9535*EXP(-ABS(E-5)/60)
E = your enthusiasm going into the game.
Running your example in the model, the highest a team can get, running TIE the whole time and staying in the cup, is 15.9, which you would first reach immediately following the 9th league game (on a Saturday). However, then the next morning, you're already at 13.7 since you're being pulled back to 5. The following morning, you've fallen back to 12.1, and then down to 11.0 before you're Tuesday game, where if you TIE, you'll bounce back up to 14.7 (multiplying the 11.0 by 1.333), and then you'll begin your descent back to 5 again until your next game where you may choose to TIE again.
Also, keep in mind that playing Normal is the same as a night where you don't have a game.
It's always been an interesting part of being in the cup, as when you are in the cup, you have an extra enthusiasm boost on Thursdays if you can use it (if you think you can play TIE and still win), but then when you're out of the cup, you don't have to worry about breaking up your lineup to manage minutes.