If there is liquid water, ice can form at any surface temp below zero. The low temp lack of icing is caused by generally (convection etc aside) there being no liquid water there, not that the surface is too cold.
I am surprised aero heating is linked to TAS rather than IAS.
Does that mean that, if you are flying in IMC in say, -15c at 195 knots, then your leading edges could collect ice (due to the aerodynamic heating) but the remainder of the wing could collect ice?
No, because (in stratus cloud) supercooled water is not supposed to exist below about -15C, so if your TAS is high enough to generate 15C of aerodynamic temperature rise, you should never ice up 
Example: SAT is -20C, temp rise is 15C, so the airframe is -5C which is a very bad temp for collecting ice, but the water droplets are at -20C so already frozen.
In reality, in higher speed aircraft, you get significant pressure drops in places so the temp actually drops relative to the static air temp (SAT – the ambient) so there can be localised issues.
But at a TAS of about 350kt you get 15C of heating so are pretty well protected from icing.
The easy way to work out the heating is with one of the slightly more advanced circular slide rules e.g. the Jepp CR-5.
The problem with using aerodynamic heating for ice protection is that the Va for most light aircraft is too low for this to be useful. Big jets can penetrate turbulence at almost full cruise speed, and they have radar which hopefully stops them flying into something really nasty.
Some sad examples of icing issues in aircraft/pilots not prepared for it.
1st one:
GUNNISON, Colo. – A pilot flying from the Denver area to Arizona was forced to deploy his plane’s parachute system when the aircraft encountered light icing northeast of Gunnison, Colo., Friday afternoon.
Light icing?
2nd one:
It disappeared shortly after takeoff from the Telluride Airport Sunday morning, San Miguel County Sheriff Bill Masters said.
Would it have iced up straight after takeoff? Also the link does not mention ice.
Second one unclear. Apparently departed into light snow and 1mile vis from high altitude airport.
Both seem more about judgement to me but also involve somewhat underequipped aircraft launching into icing conditions in mountainous terrain.
