Every manufacturer does cold weather testing - the A380 is in Iqualuit as we speak. But there are software issues with the Embraer 175 and 190 that are affecting those aircraft, and I don't believe it has anything to do with cold, but is a reflection of system bugs. JetBlue is having similar problems with its 190s. The latest I've heard is that the bugs are being worked on, the programmers for Embraer and their avionics suppliers are doing their thing, and these issues will be fixed progressively over the next couple of months.