Is it permissible to combine the Maghrib and 'Isha prayers due to the 'Isha prayer time being very late (11 PM) and the difficulty of waking up for it in the temporary country of residence?

Allah Almighty has appointed a specific time for each prayer, and it is not permissible to combine two prayers except in circumstances permitted by the Sharia, such as travel and illness. What the questioner mentioned does not permit combining Maghrib and Isha prayers; therefore, each prayer must be performed at its appointed time.