I haven't started looking in earnest just yet, but do have a couple of aspects to contribute:

1. The TPMS will be an issue as well. If TPMS sensors are not installed in the winter tires (which must be registered to the car, probably via OBD-II), the warning light will blink all winter long.

2. If you use higher profile 17" tires (as I plan to), with a similar "revolutions per mile" rating to the OEM ones, you can mitigate (or even eliminate) any computer-calculated speed/mileage errors.