I think all 2012 and later LEAFs have battery heater, heated seats, heated mirrors, etc. for cold weather use. Some late 2011s also came with cold weather package--my early 2011 did not. I don't think wiring would be there on early 2011s because the first version of the service manual that I have does not show any of the cold weather items or wiring. The later versions include the cold weather information.
The above information is for USA specification LEAFs. It is possible that European specification cars are different.
Gerry