I suggest you hold a half-day activity and send an invitation letter to your parents a little in advance, one for each.
Enter the park and do morning exercises normally from the morning. Teaching activities can be related to the Dragon Boat Festival. For example, Xiaokangxuan picture book "End-to-end Lunch", or prepare eggs and zongzi to take children to appreciate and understand traditional festivals.
After that, you can carry out parent-child activities such as making zongzi, painting eggs, and pasting bamboo leaves.
Then, when children have lunch in kindergarten, they can take zongzi and eggs wrapped by children and parents to the kitchen to make delicious food and share them.