Have you looked at alternative airports you can fly from rather than PHL? Would that make any difference (guess it might depend how far you'd want to drive, and if the flight times get you home any quicker)? They might work with you on this if you can come up with an option.

When they cancelled my SJC-ORD flights, I rerouted out of SFO without any charge, rather than going earlier out of SJC.

You can always ask if they can put you on another carrier, but I suspect they are not required to do that. Nothing hurt by asking. Just have all your options researched before you call back. It may come down to a refund being your best option in the end.

Tom in Singapore today