I can tell you here in FL, HVAC for residential services would be hard to beat, very few people are willing to go a day or two without AC in the summer which begins in March/April and runs through October. Schedule seasonal service during the winter and take time off to hunt.
I have a fellow here at the house right now working on my heat pump. Those guys are busy all year round. AC in the summer, heat in the winter.
Good clean trade and another trade that one could do on the side.
