I have limited exposure to -8 degrees fahrenheit with a digital camera and flash.(Nome,Ak. Iditarod finish 2004). My findings are that NIMH and NICAD are short lived but much better than alkaline,with rechargable alkaline the shortest of all.Also rechargable alkalines lose capacity each time they are cycled. I have had good luck with battery purchases at a local salvage chain ,lithium 8 pack for 4.88USD and alkaline batteries for ~6.00USD for a 12 pack.
Just MHO,YMMV.
Mike
The perpetually tired medic