We usually see the low voltage on holiday weekends when the demand is up. (just another reason not to camp on the big three if you can avoid it)
Also water pressure can be a cincern, but more the week after a high demand when the park owners don't turn pumps back down after turning them up for the holiday demand. We've seen campgrounds showing upwards of 80-90 PSI.
Back in the olden days in Florida, this was known as green Anaconda time. Those old garden hoses would swell up to 5-6 inches in diameter with the pressure and the hot sun. A vanishing species with the advent of white hoses and pressure regulators.