Originally Posted by corporate-wage-slave

Welcome to Flyertalk. I wouldn't leave it too long just in case flights fill up, but late September is quite a way off and as you only get one bite of the cherry there is often merit in leaving it until nearer the time. I often advocate people do not rush to do things the second a flight is changed. To give on example you may in th end decide not to travel and thus want a cash refund - if you have already rebooked then that option goes off the table. But maybe early August have another look at this.