This is a great example of why feeder stations can be very handy. If you had a feeder station in place, you may have some maggots emerging for the frogs to supplementally feed off of until FFs are received/picked up.
I have found myself without FFs too many times myself... Generally I just order online right away. However, make sure you seed/culture them out as needed asap! If things are that dire, feed the starter cultures when you see large maggots. Dart Frogs are quite hardy and will tolerate a few days(liberally...) without feeding(provided they are in good health). You should be fine.