I've spent a lot of my life outdoors and I am sure that with or without snow you could tell from the tracks (not RR tracks) if these were being carried away or not. There is no way that thieves under the influence of anything or not wouldn't drop these or set them down along their path. Even if they didn't they would clearly walk differently. Even if you did pick up a pattern on their activities you would be well advised to wait for them a night.
The way it is in Wisconsin if they hurt their backs stealing them I would be liable. I would rather scare the hell out of them because they wouldn't report it for fear of facing trespass charges.
