I wonder if a C5 fits all three pins?
No it won’t.

https://video.stackexchange.com/questions/24973/use-xlr-for-power

You’re drawing only 5 Amps, sure, and XLR cables can carry from 2 to 10 amps, but not 120 volts of alternating power. XLR cables are not meant to conduct that kind of voltage, if you attempt it, the wire could overheat, melt your connections, and potentially start a fire.

XLR is commonly used for low-voltage applications (mostly 4 and 5 pin XLR though), so you could rig up something to carry the DC power from your device transformers. Plug your power adapters into the wall, then use the XLR cable to carry the low-voltage DC power to your electronics. This will require some more fine-wiring, and there’s no guarantee the wires will carry the DC 100 ft to the satisfaction of your devices. They may not power on at all.

You’re better off using your proper power cable.