It sounds to me like the OP has already considered the flight credit idea, but has decided instead that they'd actually enjoy taking a trip somewhere between now and May. What they are seeking input is the forum's best and creative suggestions for a destination.

OP I will put on my thinking cap. It would be useful to know a bit more about your preferred travel style. When I personally hear "April" it brings to mind that I've always wanted to travel to the island of Capri during that time of year to see the bougainvillea in full bloom, but that's admittedly not everyone's cup of tea. . That would likely mean flying into Rome, which is also very pleasant at that time of year. I'd probably seek to go at the end of the month to avoid the Easter crowds, although for some that might be an attraction. But that's only what I would do and it's a fairly traditional destination - am I correct in thinking you are seeking something more exotic?