Some of these devices use AC on the sensor (making the thermistor part of an RC circuit). In the case extending the probe will probably fail. The 1.5V operating voltage makes it much more likely it is such a chip. You can test it with a cable or by adding appropriate capacitors to the probe connections to simulate the cable capacitance. If your cable is 20pF-30pF per foot you might try 1nF.

If it is DC through a typical 10K @ 25 C thermistor you can extend it to any reasonable length- the wire resistance will have no significant effect.

Some of these devices use AC on the sensor (making the thermistor part of an RC circuit). In the case extending the probe will probably fail. The 1.5V operating voltage makes it much more likely it is such a chip. There also appears to be a 10K reference resistor beside the NTC thermistor connections, so it could be this type.

You can test it with a cable or by adding appropriate capacitors to the probe connections to simulate the cable capacitance. If your cable is 20pF-30pF per foot you might try 1nF.

If it is DC through a typical 10K @ 25 C thermistor you can extend it to any reasonable length- the wire resistance will have no significant effect.