I don't see why not, as long as you are comfortable handling the engine failures and the Vmc demo without a great horizon. I can't think of any regulation in the practical test standards that say they have to be done during the day.

I've sent multiple students on Instrument rides that either were entirely at night or went into the night, but since you are under the hood, what's the matter?

Just make sure its not the first (or even second) time doing it.