Low voltage supply to ups
A general answer can't be given that applies to all devices.

Some devices use a universal input power supply that is designed to support all typical voltages around the world: 100V, 115V, 230V etc. A typical input range is 85V to 264V. Devices powered through one of these will still draw their rated power in your circumstances.

Other devices can be expected to malfunction badly and even be damaged in your circumstances. Anything with an AC motor deserves suspicion. Some devices may compensate for the lower voltage by drawing more current, which is a danger to wiring and therefore a fire hazard.

The easiest way to answer the power question is to plug in a cheap power meter between the wall socket and the device.

In any case, you're on the order of 50% below nominal, whereas even 5% below nominal is on the threshold of typical national standards. Good luck with the municipality, someone in authority needs to be convinced of the fire hazard and risk to life and property.