A coyote hide is fine on an old beater Cub as a prop cover. But lets face it for FancyRestorations; and Carbon Cubs a real "Arctic Wolf" pelt is the ONLY way to go! Classy aircraft deserves a classy prop cover.......And if your a classy Lady pilot; the rummor on the "muktuk telegraph" is, Lynx is in this winter; For ladys with Carbon Cubs........ Just sayin.
Lynx would be nice, but let's be practical for a moment here- Wolverine would be the choice of true winter pilots. Ice won't stick (why they are preferred for parka ruffs). So a set of Wolverine covers would be perfect, and the yellow stripes would match real men's cubs.
Now, about heat and such- a couple of important things. IF you have electricity, the world is your oyster! A blue tarp bungied around the cowl and a Kmart little bitty area heater will keep your cub engine warm to zero or below, or warm it up. A little cooler? toss a stupid second hand blanket under that tarp.;-)
Now, the challenge comes when you plan on flying away form electricity. Yes, we might plan on being home later, but we do get caught on occasion. I have an Alaska Wing Cover set and engine blanket. Bulky if you don't roll and tie it into the sack, but I don't care. I park on a river bar below zero for a few days at a time where I don't have electricity; when it comes time to warm her up I want to hold all the heat possible. Some day I will get a good look at the thin ones everyone says are so great... but until I find one that keeps it as warm as my thick one I will keep using it.
Wind: Your cover can not allow wind to penetrate. Just open your car window a smidge and see how long your car stays warm inside with the heater off. There is a relationship between how long it takes to heat, or cool off, and the air allowed to depart. gaps are the biggest issue so get a quality fitted cover.
Another factor that was emphasized to me my first winter trip to the cabin in the Maule the size of your engine compartment makes a difference. With the same heat source I used on the cub, my engine temperature was much lower with the bigger engine. Old story- every cubic foot takes x amount of BTU's. Bringing an O-540 from -15 F to 32F+ takes more heat than the O-320, and the cowl has more surface area to loose heat.
We had Reiffs on some planes in Bethel. Fantastic system. No fuss, no issues. Some of our planes had the male plug built right into the boot cowl. On a cub just have it inside attached to the engine mount and go. However, the simple electric heater with little fans kept the engines just as warm over night- for far less money. As long as you have electricity and your snow plow operator doesn't take out your extension chord keeping her heated is a piece of cake.