Myself and Rosie my assistance dog love to attend pride events but things like this make me dread them because if you cant get simple things like this right I have more doubts about more complex needs being met and is a sign we won't be welcome at an event or will have a multitude of access issues

Pt2
Replacing some dry food with wet and hydrating their food with water or low salt broth can help too, the water is shown to help dogs feel full longer so they aren't ravenous when their meals get cut down, plus increasing exercise will help

Replace some of her food with green beans, carrots and peas, the fiber helps them feel full. Also look into a weight loss food or a lower cal per cup food because they eat the same volume but loose weight so feel less hungry, I like the hills weight maintenance kibble