Back when we were rodeoing, a place like yours would come in handy sometimes for a layover if we had a couple days between rodeos and not very many miles between. A good place to turn out and let them roll (other than the arena after the rodeo, at the end of a lead rope) and pick a little was worth a lot to us. Hookups were unecessary, as we had a generator on board (but keep in mind the noise they make for you guys). When I first started, I couldn't sleep for the generators running. By the time I quit, I couldn't sleep if one wasn't running. lol Anyway, you'll need to find some people going in your area, and see what popular associations they are in, and which events are held in your area: Barrel racing, rodeos, cutting, racing, etc. Then advertise in those type association magazines. Get the word out within the circles you want to cater to. Maybe get with the event directors to take care of the overflow, that would be the best imo. Once that event was over, you wouldn't have to deal with them any more. Make a little quick money, then back to normal. But you will need to be pretty close to this event.
As with anything, you will have some trouble, some people's kids are not very much fun to deal with. And horses should be extinct, given what all will kill or cripple them. Change of weather, change of water, change of feed, standing on the wrong shavings, eating the wrong leaves, eating off sandy ground, hay too fine, too much water too fast, not enough water, twisted gut, possum chit on hay, just about anything you can imagine.