Hello Mick – this is weird. I also play guitar and mandolin, and I too spend Februaries in the Fort Lauderdale area.
I get the impression that there aren't many sessions around, but I've been to a couple of bluegrass ones and had a great time – I take the mandolin for that. Everyone is friendly and welcoming and I really enjoyed it, and certainly hope to go again this coming February.
But I also play a bit of folk and a bit of swing, and I think your idea of doing something that combines all three sounds like something I'd very much like to do too.
Perhaps we could get together for an afternoon or evening somewhere?