The general consensus seems to be to keep this within the group, or at least not to advertise in local media, on fliers, etc. And that makes sense. So once I finally talk with this family, I will set a time, and let's see if we can fifty costumed people and a cheering section there. I think we can do it.
I guess the only reason I wanted to do the fliers was because once I put up about 3,000 fliers advertising my younger brother as a professional cat groomer (with a coupon on every flier for one free grooming session), and the resulting months of bizarre phone calls that my unsuspecting sibling received still give me joy to contemplate all these many years later.
But this is different, and we do have to worry about the little kid's safety.