OK, here's my suggestion from exactly the same situation. Lose the wb cage on the seat tube...you don't need it unless your commute takes you through Death Valley. Attach your frame pump to the top of the top tube w/old school metal cable guides. Place the u-lock frame attachment on your seat tube so that the u-lock doesn't hit the TT and clears the wb. As you'll be running one wb get a 28 oz for extra. A thermos of the right size will fit as well for winter, hot liquid commuting.
I did it with a triangle the size of your Schwinn. It's tight, but it fit. It's all a matter of compromise.
PS: Just saw that your lock didn't come w/t frame mount as advertised. Call them and have them send you one!