Is it permissible to perform congregational prayer at home, and is there a difference between this and delaying the ‘Isha’ prayer to play soccer, and is it permissible to perform congregational prayer in the stadium?

There is no difference between your action and his action, as both are permissible according to the majority of jurists who do not stipulate the mosque for the validity of congregational prayer, and impermissible according to those who deem congregational prayer in the mosque obligatory. Nevertheless, this action of yours causes you to miss out on a great virtue, which is the virtue of witnessing prayer in the mosques, regarding which many texts have been narrated concerning the virtue of walking to them and populating them with prayer, such as His Almighty's saying: "Only those shall maintain God’s mosques who believe in God and the Last Day, and establish prayer and give zakat and fear none but God. It is they who are expected to be among the guided." And praying in the mosque has a greater reward and is more preferable than delaying it and praying at home. It is advisable to preserve congregational prayers in the mosques and not to be negligent concerning them, and to choose a time for play that does not conflict with prayer in the mosque.