The big question for me would be: was the demon summoned from someone who lived there or not? If the summoner lived there, the threshold is gone, no discussion. A resident corrupted the purpose of the home, there is not going to be much left to call a threshold.
On the other hand, if the summoner was a guest or even forced his way in, the impact is not going to be that big. There still is going to be an impact though, but it should heal over time, if the home still is a home after it, of course, other wise the decay would continue.