Is it permissible for a Muslim to return home to pray in congregation with his family, or should he pray alone in the mosque, if he missed the congregational prayer in the mosque and a second congregation was not established?

We advise you to be keen on arriving early for congregational prayer. If you arrive after the congregational prayer has finished, your prayer in congregation with your family is better than praying alone in the mosque. This is because the essence of congregational prayer is found in both places, and while the mosque has a distinction, if one prays in congregation at home and then prays alone in the mosque, then praying in congregation at home is better.