Gary, it sounds like zardox is for warm temps and slush. I have the opposite problem in Montana. The skis tend to stick whe I have wax good for 10F-32F and I get temps that are sub zero F. If I know it's coming I can put a layer of Swix Extreme Cold powder on the night before and that really helps, otherwise youu are better off with no wax at these temps.
Nice to have a solution that works and can be apllied on the mountain!!