Is one sacrifice sufficient for the one offering it, for guests coming from other cities, and for all their families?

A single sheep is sufficient for a man and his household, based on the hadith of Aisha (may Allah be pleased with her) that the Prophet (peace and blessings of Allah be upon him) sacrificed a ram and said: "In the name of Allah, O Allah, accept it from Muhammad and the family of Muhammad and from the ummah of Muhammad." This hadith is used as evidence for the permissibility of a man sacrificing one sheep on behalf of himself and his household, and they share with him in the reward. As for those who are not members of his household, they do not share in the sacrificer's reward.