Prius tire pressure sensors are fully removable. However, they may or may not fit inside your new wheels. They 'ride' on the inner rim of the wheel. Toyota actually has two styles and they change between various wheels.

If worst comes to worse, you can keep the pressure light off by dismounting the spare tire, attaching all the sensors to the inside of the wheel and remounting.

I have heard of people dropping them inside the spare but they're not very durable and if you had to use the spare, I'd be afraid you'd break them. They aren't cheap. We also had a guy build a metal box with a valve stem in it, so he could pressurize the box (with sensors inside) and store it inside the car. Don't know how that worked out though.