If the wing is not contaminated, it matters not one jot what the IAS is, or indeed the weight. The stall will happen whether you like it or not at VS.
The AOA indicator (if you are lucky enough to have one fitted) will indicate your margin relevant to VS. VS is 1, and you will approach it as the AOA increases through 0.6 (1.3 Vs) to 0.8 (1.2 VS which just happens to correspond to V2), and then to stick shake which will occur at a pre-determined AOA (not IAS) determined by the manufacturer. At 1.0 the airplane will stall. Irrespective of WAT.
It makes no difference whatsoever if the airplane is fast or slow, with flaps or not, fat or thin, high or low, cold or warm - AOA will tell you the truth on an UNCONTAMINTED wing. If you have an AOA indicator you need not even bother to calculate Vref, V2, best glide, or even whether you can climb another 2000 at your current weight.
Magic springs to mind when considering the usefulness of the gauge, and stupidity for it not being fitted to all turbine aircraft. Almost everything in a FBW airplane is determined by AOA, so why not let the drivers read it?