As a fellow Albertan and an avid photographer I understand your issue with electronics.

I use a chest pack camera bag for my digital SLR, when snowshoeing and skiing, and use reusable hand warmers in the bag to keep things functioning. The padded bag insulates well and I can usually work for a couple of hours before I need to add a new hand warmer.

The camera is usually out and back in the bag fairly quickly so it does not cool down that much. For other electronics like GPS that might be out for longer periods of time I will sometimes tape one of the disposable hand warmers to the GPS to keep it working. The disposable hand warmers need to interact with oxygen to work so do not seal it up with tape so that it can breath.

For water I use a Nalgene bottle in an insulated jacket and will drop one of the reusable hand warmers into the bottle to help keep it from freezing. The reusable warmers are usually made with food grade material so I am not worried about them possibly leaking. The Nalgene is usually my primary water source and I keep a thermos full of hot water wrapped in clothes deep in my pack as an emergency supply of warm water.