A freind, ex-military, has a new military Tennier extreme cold down and ployester filled sleeping bag I can borrow for the musk ox hunt. Anyone have any experience with one of these bags? The outfitter said to get a bag rated to 0deg and this one is rated to -20. Sounds like it should work. Heres a link to one on the web.
http://www.gr8gear.com/index.asp?PageAction=VIEWPROD&ProdID=343

I hope there will be a furnace in your tent.