Elk season for us ends in Oct. and Whitetail goes to Nov. 30th. in some areas. This, in BC, where the ambient temps. will go down to 10*F usually at night and sometimes colder.
Depending on YOUR size/build, I would buy a suitable WM bag rated to 0*F, or, a Valandre Shocking Blue, as your main BPing bag.
I usually carry an original Integral Designs North Twin bag for this, it is WET here and I have used for weeklong stints below freezing in remote wilderness horsepacks and 2-3 night backpacks with complete satisfaction.
It is Primaloft, it has been wet, but, I was warm and dry in a tarp shelter.
Don't know about the new down, if I buy another down bag, it will be a WM Badger or Terralite as I have superb custom ID winter down bag.
HTH-if it will fit, Brad's suggestion is spot on.
