Accuracy of the internal temperature sensor

Since 1v48, we can call E.getTemperature() in order to retrieve the chip internal temperature. I just read from the datasheet

the internal temperature sensor is mainly suitable for applications that detect temperature
changes instead of absolute temperatures. If an accurate temperature reading is needed,
then an external temperature sensor part should be used. ```
As well as in the reference manual: 

The temperature sensor output voltage changes linearly with temperature. The offset of this
linear function depends on each chip due to process variation (up to 45 °C from one chip to
another).```

I actually never tried to quantify the real accuracy of this sensor. Does anyone have any idea on the actual accuracy ? Does anyone already used an Espruino that has a temperature offset around 45°C ?