DEF would not have a weather delay.

Thanks for the link to the other thread. I missed it on my initial search. The answer isn't what I was hoping for but what I was expecting.

In this case what would you do if it looks like the initial flight out of ABC will be canceled? Call the airline for an itinerary change when jumping into the car to drive the 4 hours to DEF? That would be at least 5 - 6 hours before the flight out of ABC departed.

Can you just tell them to change the itinerary so that you are dropping ABC (both directions) from the trip? The fair is nonrefundable but there is a $100 fee for any changes.

My concern is that the flights are filled (no seats showing as available) so if they have to cancel a ticket to reticket isn't there a chance of losing those seats to someone else given the millions of people hitting the reservations systems all at once? And, if its a reticket I wonder if the fares would be more expensive.