Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
1- When one misses a certain prayer, he must pray it even though its time is finished. He cannot delay it until the similar prayer time comes again.
2- He prays it whenever comes to his mind, even if it is during one of the times in which it is prohibited to pray or even if it is during the time of another prayer.
3- If one fears that the time for the present prayer will be missed, he prays the present prayer first and then prays the prayer that he had missed afterwards.
Answering your question, Sheikh `Abdullah ibn Jibreen, the late prominent Saudi Muslim scholar, stated:
Making Up for Missed Prayers
Prophet Muhammad (peace be upon him) said: “Whoever sleeps through a prayer or forgets it should pray it when he remembers it and there is no expiation for it but that.” And then the Prophet (PBUH) recited the Quranic verse: “Establish the prayer for My remembrance.” (Taha 20:14) (Al-Bukhari and Muslim)
Offering missed Isha prayer
Based on this Hadith, there is no difference between the Isha Prayer or other prayers. When the person wakes up, even though its time is finished, he must pray it at that time and cannot delay it until the similar prayer time comes again. He prays it whenever comes to his mind, even if it is during one of the times in which it is prohibited to pray or even if it is during the time of another prayer.
However, if he fears that the time for the present prayer will be missed, he prays the present prayer first and then prays the prayer that he had missed afterwards.
Almighty Allah knows best.
Source: Islamic Fatawa Regarding Women, Compiled by Muhammad Ibn Abdul-Aziz Al-Musnad and translated by Jamal Al-Din Zarabozo, Darussalam, 1996.