There is a contradiction between this two sentences.
How do I tell Lightroom to color-balance
the sodium vapor lamps are the color they should be
The sodium lamps are more or less that orange-yellow you have there.
A color ballance is cheating the image so the image looks as if was shoot with white light, so a white wall looks white, or neutral gray.
So it is a contradiction.
Option 1: If you have a preset, for example go another night with a gray card to another street with the same lights you could use that as a profile.
You open that image, color balance it, and use that same profile on consecutive images.
Option 2: Use an object that you think is white, like a specific wall. I tried to use the light iself, but as it is blown, the measure is not accurate.
Option 3: On Photoshop. There is a method that works decently on several images, and the result was not that bad.
1) Add a layer 50% gray.
2) Change blend mode to diference.
3) Add to that layer an adjustment layer: Threshold.
4) Slide the, oh well, slider to the left, where you can see just some small black areas. That is a "gray" point.
5) You can mark it with the Eyedroper + Shift.
6) Delete that new masks and with the levels window, use the middle eyedroper to target that region you marked.
Obviously the color range is very croped because the limited spectrum of the sodium lamps.