-40*C? That's scary! I think the coldest weather I've seen was maybe -9*C. Yeah, a mobile home wouldn't work cause they are made of metal. But they do have modular homes that can work. Here's one example:
Arctic Mobile Unit Keeps North Pole Visitors Warm | Inhabitat - Sustainable Design Innovation, Eco Architecture, Green Building
That's a small one for the North Pole but they probably make them larger too.