You could also consider to decouple the sensor from the Christmas ornament an broadcast the values over BLE or WiFi. That way you could place the sensor in the window without rethinking the rest. I think the greatest disadvantage would be that you have to relocate the sensor with the ornament.
Another important reason to not start over is to make it a habit to continue playing even when you make a mistake. If you are performing and you make a mistake, then you don't want to just keep on playing.