Your FP for the down ride will still be honored once the ride is back up, even if the time window has passed. You may also be given the option to use the FP on another ride of your choice. This may not include headliners though. We recently had a FP for FEA, it went down and we rode Soarin' in its place. The is no action required on your part to take this option. You just go to the FP entrance of the replacement ride and scan in as usual. You will get a notification via MDE telling you what rides you can use the FP on.