We went late Jan/early Feb in 2006 and it was bitterly cold!
We went back last year mid Feb. It was cold but bright and sunny. We would have thermals on one day and no coat on the next.
We are going again on Feb 11th for 5 days and i will pack all of my winter warmers, coat, jumpers, jeans, warm socks, thermals, gloves, hat, scarf etc.
I think its best to prepare for it to be cold and if its not then thats a bonus.
I will put up with the cold for the low crowds and i also can't wait to go on TOT. The one in WDW is one of my favourite rides!!