This may be a really stupid idea, and if so I'm sure that somebody will correct me, but why couldn't a pyramid style tent be made of non waterproof fabric for very cold climates? WB fabrics have issues with condensation and so do double wall tents if sealed up too well. Rain is not likely, and even if it does rain, wouldn't a DWR treated nylon keep the water from seeping through if you did not touch it? In the 70's and 80's I spent many nights in old canvas scout tents that never leaked if you did not put your hand on the walls. (The oil on your skin would provide a pathway for the water to leach through the fabric) Now admittedly cotton swells up when it gets wet, but most nylons are tightly enough woven to keep out the wind so with DWR shouldn't they keep water out?

Anybody care to comment?