The link shows 0.8% precision. with a 10-bit ADC, that means that the voltage reference error is basically corresponding to 80 ticks of the ADC. 0.8% of your 140°C full span means 3.2°C.

Note also that you can't just calibrate for the 0.8% error - it isn't constant but depends on temperature, and ageing. This all besides the ageing in the thermistor and any other critical components in your design.

When the world isn't full of cheap thermometers with 0.1°C or better precision (besides 0.1°C or better resolution), it may be suspected that it is hard to design such thermometers at a low cost. It's even hard to design them when you have a quite large amount of money available to buy components for.

If you do get a thermistor sepcifically designed for better precision:
http://www.omega.com/ppt/pptsc...S_ELEMENTS
you suddenly have to realize that the price of the thermistor does not show it as a cheap alternative to a Maxim one-wire sensor. And notice that the precision of the thermistor does not include errors introduced from your ADC, the voltage reference, the constant-current source, ...