We've been asked once, in hundreds of gigs. It was at an English Heritage site, probably one of the grandest houses in the country. The sockets are all under the floorboards, to keep them out of sight, only; having been recently refurbished, the workman had nailed the removable panels from the floorboards down. So we had to daisy chain extension leads from an outside power source in the belting rain. It wasn't too exposed, just, very frustrating given how fussy they were and given the list of rules we had to adhere to that something this simple wasn't checked.