I have an upcoming FWA==>MSP==>LAS flight with a 35 minute layover in MSP. I have been monitoring the FWA to MSP flight every day. Today it departed FWA 5 hours and 5 minutes late, and landed in MSP 5 hours and 36 minutes late.

On the day of my trip, if before I leave the house I check the website and see that there is a multi-hour delay leaving FWA, what would be the recommended procedure? Should I call Delta and try to get on another flight? They have a FWA to LAS route that departs FWA a couple hours later than my scheduled flight. It connects in DTW instead of MSP. If they have open seats on that route, would they put me on those flights? Is it first come - first serve, so the earlier I call the better?

It may be relevant to say that I have have no status with Delta. I'm flying on Skymiles earned with my AmEx Skymiles card. I'm probably Delta's lowest priority customer. I'd guess that there would be higher priority customers making the same request for a change of flight.