Question about the Keep Warm function

I have a school potluck tomorrow, and was planning on making a rice dish (chicken biriyani) in the instant pot tonight. I'm going to refrigerate the food tonight, and was wondering if I could bring the whole instant pot to the potluck and use the Keep Warm function to heat it up? I get to school at 9am and the potluck is at noon, so it would have 3 hours to warm up (but I wouldn't be free during those 3 hours to check on it). Is it better to just bring the food in small containers and heat it up with a microwave right before the potluck? I just don't want the rice to burn at the bottom if it's heating up for 3 hours unattended.