Originally Posted by
Often1
Not necessarily. If booked as a round-trip and DL cancels or significantly changes either segment, you are due a refund of the full ticket. If, booked as two one-ways, all you get is a refund of the cancelled segment and a funny money credit for the one which still presumably flies.
All of these "what's best" revolve around the central question of whether the credit is useful to you.
In my experience DL is pretty flexible when that happens....but yes that is a possibility. There is a MUCH higher possibility though that one segment will go down in price or you will want to make a change to one of the flights and don't want the other to get repriced.