I've insisted several times that guests stay for five nights, once because of a winter storm, once because my wife and I really liked the guy and he seriously needed rest and he cooked great, once because of extreme summer heat and the guests' trip timing. In all cases they were prepared to move on after one night but we insisted and enjoyed the company.
Another time we felt we were taken advantage of, very slightly, after an arranged prolonged stay, nice folks, but no feedback on the site, just disappeared into the ether.