Second set of wheels question

So I love my new Prius but I live in Vermont and the OEM tires are beat for up here. I am looking at a second set of wheels/snow tires. My question is what to do about the tire sensor monitors. DO you need to get a second set (big bucks), is it straight forward to move them from wheel to wheel, do you need a Toyota dealer to do this etc? How have you all handled this?
Thanks!