Setting in the rut with snow/rain/freeze/thaw can get you in trouble. Not to mention you stand a much greater chance of having your traps run over.
I just lost two at the very end of a deadend farm road, one of my best red fox locations. Two traps destroyed in one pass.
I occasionally set in the rut but found that if I dig a stepdown set and make it as small as possible with good, sharp edges (these don't have to be visible to the animal, you can blend them in), sometimes they can be run over and not even sprung.