Currently in CAI and I have the second portion of my ticket back to LA. I'm scheduled to fly CAI-LHR-ORD-LAX. The ORD-LAX layover time was increased by 20 minutes (from 7:10 PM departure to 7:30 PM departure). Is this sufficient for me to get a free ticket change to fly on a different day? Perhaps the day before or a few days before?