My own personal opinion is that the battery location is a very large part of the issue with cold weather starting. The size of the cables required to reduce voltage drop under load during extreme cold is also an issue. The battery is located to far from the starter and the connecting cables between are undersized for the VD. The cables are rated for the current however at a cost to the supply voltage.
I had five sleds all in the same conditions, three Apexs (two 2012 and one 2011) and two SR-Vipers. The Apexs started as they always do in extreme cold with some cranking but the rpm of the cranking was not diminished from the cold. The SR-Vipers tried to start but the cranking was so slow that they would not turn over. Hooked up cables to a truck, effectively removing the voltage drop and they fired off better than the Apexs. I have always thought that the battery located at the rear, as far away from the starter as was a ridiculous idea and a design issue that should not have been over-looked. I really wish someone would develop a battery relocation kit for the SR-Viper all models.