Good old dry dirt seems to work for me once the temps stay well below freezing. The moisture doesn't condensate on the dirt, and it remains dry for a good period of time. The one thing I found is that this works better once the ground freezes, and doesn't necessarily work during deep freeze periods earlier in the season. I say this because I've had dry dirt collect moisture even when the air temp is well below freezing, but have to think the ground temp was high enough to cause this. Once the ground is forzen, its not a problem. Glycol seems to loose its kick around 15 degrees from my experience, and this is mixed 50/50. never tryed to mix it richer, so can't really say if that would help.