To get around this 'problem', run your heater in recirc mode, with the temperature set higher than ambient (which you'll want to warm you up!). The temperature seen at the temp sensor on the evaporator will then be higher than 2-4 degrees, and the A/c will function as a dehumidifier.
The reason they have a sensor on the evaporator to shut the compressor off below this temp is because any condensed water on the evaporator matrix will freeze and block it - the a/c system in a car works by convection (i.e. blowing air through the evaporator). The refrigerant and compressor will quite happily freeze the evaporator solid, but that won't help with cooling or dehumidifying the car.