There are a few challenges with cooling a sensor: it takes power, it requires a lot of air cooling, and condensation problem. The last one is the reason I chose WG-2 for hacking.
WG-2 is an adventure-proof camera, and it is airtight! This means I can remove all moisture from inside, completely eliminating frost on sensor.
It also happens to have a very nice construction, that allows to expose sensor back surface to the outside for cooling, without much trouble.
Read on in project logs!
<spoiler>for this camera, cooling down to -25°C (-13F) is pointless</spoiler>