Which is better: delaying the 'Isha prayer to perform it in congregation, or performing it with the first congregation at the mosque, knowing that it is recommended to delay it?

Delaying the 'Isha prayer is preferable if there is no hardship and it is possible to pray in congregation, based on the hadith (definition): "Were it not that I would overburden my Ummah, I would have commanded them to delay the 'Isha prayer until one-third or half of the night." It is desirable to delay it until one-third or half of the night, provided it does not cause hardship to the worshipper or overcome him with sleep, and provided there is a congregation with whom to pray, as congregational prayer is obligatory.