Many Eliminate the stagger and use 225/40R18 front and rear. This works very well for winter and results in better winter traction. You can use either run flat or non runflat tires for winter use.
For TPMS, Are your original equipment valve stems rubber or metal? When this vehicle is equipped with OE rubber stems, it uses a system that does not use pressure sensors. Instead, we it uses a system that detects how many times the tires rotate/spin in a given distance (a tire low in pressure is deflected and rotates more often per mile). If one tire spins more often than the other three, a warning is sounded. This type of system does not use TPMS sensors. If they are metal, it usesTPMS sensors.
We do have 17" wheels that will fit the car for winter using a 225/45R17 tire size on all four corners. There are handful of wheels we carry that will clear the brakes and work well. Two of the more popular choices have been the Sport Edition A7 and Rial Salerno.
More information is available in the winter sticky post at the top of this forum.