How can one reconcile performing the Maghrib prayer on time and having iftar at home, given the family's desire for a communal iftar?

It is possible to combine observing the Maghrib prayer in congregation and breaking the fast with your family by breaking your fast with your family first, then going to a mosque that delays the Maghrib prayer, or by having your family wait for you until you pray and return to them. If you break your fast in the mosque, it should be a light meal of a few fresh dates or dried dates or water, and then you return to break the fast with your family.