Changing or canceling an award after travel has begun
There are some older threads on related subjects, but nothing that really covers my situation.
I have an award booked with one domestic segment, a long layover, an international segment, some time at this destination, and a final international segment. Let's call it US1-US2-INT-US2. My plans are now changing. I'm definitely flying US1-US2, but I need to push US2-INT-US2 by several months. I know from reading the other threads that I can make date changes to US2-INT-US2 after flying the US1-US2 leg, but would I be able to cancel US2-INT-US2 after flying US1-US2 and get back the mileage difference between the original itinerary and the new domestic one-way? (I don't care about the fees, but just whether this is even possible.) I may have to rebook US2-INT-US2 outside the ticket validity window, but may not know until after flying US1-US2.
My alternative is to simply change the award now to the domestic one-way and pay the change fee, but if I can avoid the fee, that's always better.