Running a computer at -1* can make it perform faster and for a longer time so cold had nothing to do with it unless it got snowed on. Just coincidental. We spray liquid nitrogen on computers to overclock their speeds for fun and competition. I hope you find out the cause and get it fixed!
There are so many things wrong with those comments that I don't know where to start. All electronic devices have operating ranges. Just because one device behaves correctly or better at some temperature doesn't mean they all do. From the manual:
Environmental Requirements
Operating temperature: 5° to 45° C (41° to 113° F)
Non-operating temperature: -20° to 47° C (-4° to 116° F)
Relative humidity: 5% to 95% non-condensing
Maximum altitude: 3000 m (10,000 feet)
By the way, the operating and non-operating temperature ranges are not very wide. This post helped bring my attention to this and will help me keep my unit in the recommended conditions.
I hope your unit comes alive or gets repaired. It is not clear whether the warranty will be honored if the unit is proven to be exposed to temps outside the range.