I think the possibility of a screw drive being pedalled through snow would be quite unlikely. I think the grunt required would be a killer. Snow isn't uniform and the variability would adversely affect the pedaller. Water however could see the entire screw under water and would work quite well. Some experimenting to get the correct buoyancy leaving the screw in the water and the rider out of it will be needed. It'd effectively be a pedalo which aren't cheap to buy. It could also be in in-line tandem form with longer screws. I suspect the leisure market would love to see something like this.