All weather DSLR

there's nearly no DSLR camera in that price range meet your extreme weather condition. You must allow the camera adapt to the rapid change air temperature. Refer to the camera's manual for more details.

For example, moving from cold a/c room to hot&humid outdoor ( very typical Thailand's weather ), I'd take my camera storing in a small camera bag for at least 5-10 minutes at outdoor temperature. Let the camera readjust for the temperature then later start shooting.

On the contrary, moving from warm heated indoor to cold outdoor ( your typical Canada's weather ), keep the camera in your hand-carry bag for 5-10 minutes as usual before start shooting. In the cold environment, you'll need a few extra batteries. Keep the batteries close to your body that's to keep them warm and ready for operation.

I'd not suggest any DSLR plastic body camera. Magnesium alloy body will be better off against the corrosion. Either Canon 7D or Nikon D300s ( and also upcoming D7000 ) will suit you best. Good luck.

I've never had a problem with condensation, at least from a damage standpoint. As far as a weather-sealed camera (and lens) is concerned, you could get a Pentax K-7 with the standard kit lens (make sure it is the WR "weather resistant") for about $1000.