How Small Is Too Small?
Shmoth (Exodus) 12.4 “And if the household is too small for a lamb, then he and his nearest neighbor shall take according to the number of persons; according to what each can eat you shall make your count for the lamb.”
Here we see the most reserved, conservative effort to spare the unnecessary suffering of the Pesach (Passover Lamb) while we see the in-gathering of the smallest number of Israelites into a Chavurah (Communal Gathering) or group!
Passover is the festival of inclusion. Invite a neighbor!