I've been getting acquainted with a 2011 wrx for the last couple weeks. Initially, I thought we had a wacked out cabin sensor because '65' always seemed too hot. I was using the system in manual mode for fans and vents, ac off.
What seems to work in Winter: set fan and vent controls to auto, temp to 65. Initially, the AC light will be off. As the car warms the cabin will become too warm, the AC light will go on, the cabin will stabilize at a warm-ish 65 and I find that after at least ten minutes I can punch the ac button off and all is good. I do wish the thermostat would turn down to about 60. Especially on short trips, I always wear a jacket in the car and '65' is just too warm.
The full counter clockwise position on the t-stat is heat off, and happily it really *is* heat off. Manual control subies always seem to be blowing some hot air in somewhere (driver foot well) and that got really annoying.