Danny;

General Rule: The thicker the wire (more cross-sectional area for current to pass through), the lower the resistance. IE: double the C-SA, halve the resistance.

But...the resistance over the range of the sensor is known (the length of the resistance wire is not without removal and measurement..you could certainly estimate it...), and the trick is not to change that and keep the readings similar, so I'd say the technique is to measure the wire dia./gauge and the resistance of the entire length, then, if it's not possible to repair (by soldering, a solderability test would have to be done, but as far as I know, nichrome solders OK), procure a replacement length and install...the trick there is to wrap wire under tension and with consistent spacing (equal to original)...best IMO, would be to repair if at all possible...BTW, loosing a couple of windings would bring the world to an end either...

Cheers