Please don't take what I say the wrong way. We have actually ridden together once with substructure and kensuf on the non-existent hills of central Florida. I think that it was over a Thanksgiving weekend a few years ago. I was the guy that you said was a "camel" because I hardly drank any water.
Concentrate on dropping a few pounds. You were fit enough to survive the ride you describe then, but being a little lighter would make it easier. "Racer" intervals will not actually make what you want to do that much easier. Instead I'd look at LOTS of Zone 2 with a decrease in caloric intake and drop some weight while building endurance.
And where the F is this ride? Not Florida, for sure!