I don't know of any way to adjust it, but the last time TPMS went off for me, I was almost 10 pounds low on all corners (27 down from 36 - I go a few pounds above recommended), oops!
How low is the tire pressure when it goes off? If the TPMS is giving a false alarm, you should have your dealer check it out. My brother had an issue like that with his '08 Hyundai. If the pressures are actually low enough to trigger a legit warning, I think the system is doing it's job and you should top them off. People in colder climates may have other advice or experiences to share, but maybe just putting in 1-3 pounds extra during the winter might help to avoid temperature fluctuations setting off the alert...
A quick search brings up a lot of similar questions from various car owners, but the general consensus seems to be that it can't be adjusted.
I'm sure you already know this, but on the I2, you can just press the down arrow on the steering wheel controls to cycle the MID screen to something else besides the warning. This is not a fix, but at least allows you to get to a useful MID screen besides the warning, and it will still continue to show up on every start until you fill the tires.
This is my first car with the monitoring system, and personally I think it's a nice feature and helps remind me at times when I'm forgetful or lazy.