The decay timer has started. I wouldn’t make a significant investment in building something on it. You could mill a bit of wood out of it with a chainsaw mill, or harvest some curable firewood out of it. Or you could remove the secondary stub, cut the main trunk at a prescribed height and carve it into something or put a birdhouse on it.
As for the stump, a local tree company could grind it with a Bobcat stump grinder in about an hour of machine time plus whatever their trucking rate is to get the machine there and back to their shop. If they have other stump grinds in the area, you can often share the mobe and demobe cost across other neighborhood jobs.
I do most of the estimating for a tree company up where I live. Sorry to see your house got rocked.
That's the neighbors house. My house is all good. But all those trees to the right of the fence are mine... Lot of stumps to get rid of.
It may sprout new growth in the spring. We'll see.