I'd rather be too hot than too cold, too. 30C is damned uncomfortable, but if you are careful you can manage it. -30C is basically Mother Nature trying to kill you as quickly as possible, and you better hope that you're either extremely well dressed, or you can get inside within a few minutes.
When I was much younger, I actually had a job that required me to work outside in the winter, and there was a stretch where it was -50C. That's my touchstone for comparison in life for misery, weather wise.