I currently use a regular 50 foot power cord rated for 15 amps. I use it only for two laptops and one camera, making a draw of about 5 amps according to the "input" label on the power supplies.
The 50 foot cord is heavy, while I notice 100 foot XLRs I have are a pound lighter. Considering both are three wire cords, I thought that there might be "power over XLR" in some way.
If not, would it be safe to snip off the ends of an XLR and attach standard power plugs that you can buy at the hardware store, assuming I never try to draw higher than 5 amps?