Does missing the virtue of the opening "Allahu Akbar" (takbirat al-ihram) in congregation necessitate re-performing the prayer, when it is missed due to sleep or difficulty reaching the mosque?

Whoever prays for forty days in congregation, catching the first takbir (Takbirat al-Ihram (definition)), will have two immunities written for him: immunity from the Fire and immunity from hypocrisy. This reward includes one who prays as an imam or as a follower (ma'mum). The congregation can be attained in the mosque or elsewhere. Preserving the Takbirat al-Ihram is a good thing, but this should not lead one to abandon prayer in the mosque, as it is better for those who are able.