You need extremely fast growing trees that are aggressive coppicers if you plan on keeping your house warm by sustain-ably managing 2/3s of an acre. Ironwood is neither. 2/3rds of an acre of Ironwood wont keep you warm. I would recommend black locust, coppiced on short rotations. Its fast growing and very dense. Its only con in your case is its young branches and stems (and thats all you are going to have is young branches and stems!) are covered in thorns. But if you wear protective clothing you should be fine. Other options to consider are hybrid poplar and willow. But they are not as dense as locust.
Ive burnt black walnuts nuts and they produce loads of heat. Around here people cant be bothered preparing BWs for eating and just throw them out with the rest of the yard waste. If your neighbours do too dont forget to scavange them too for burning or eating.
Last year I bought a Sedore stove (
https://www.sedoreusa.com) , they are pricy but can burn any biomass including woodchips, pellets even used coffee grinds. Maybe consider one of them? You could chip up the tops of your black locusts and then burn all of the tree.