Wow - you should have posted here before you decided to cancel your trip. I would call and try to re-route via DTW, MSP or SLC. Look for flights into TPA or MCO (all with connections via DTW, MSP or SLC). You can even look into driving to CVG and getting on one of the non-stops from there.
If you do decide to cancel your voucher should be refunded though - call back and keep records of your conversation and ticket number etc.