I don't know about the Limited seats, but the Touring seats take a couple minutes to heat up, but eventually get so hot that you better not have change in your pockets. The heat feels great, but it gets hot enough to heat up metal to the point of it being uncomfortable. That leads me to believe that there's something set differently, meaning, hopefully adjustable.
If you think they are too cold, I'd have it checked out. I rarely used my 2010 Outback Premium's heated seats for more than a couple minutes, because they were too warm.