Jrutledge
I live in Tok, Alaska where the winter temps are truely severe. You don't really flinch until -65*F outside. I don't even plug my '05 in until 0*. I have even got it to fire at -40*F without plugging in. I usually cycle the preheat twice before attempting to start it. Good batteries are a must and take apart and clean all battery cables yearly. Good luck.
'05, 2500, jacobs brake, webasto preheat, k&N, 125k miles