Garage Door Key Release

I have a quick questions. I just installed garage doors on a detached two car garage that has no side door. I installed two garage door openers with battery backups as well. At some point, I am considering adding a door to the side of the garage, but I am not sure yet and it would not likely happen until next fall. With that said, do I need to install an emergency key release on one of the doors? I don't want to drill into the door to install the key release if I decide to add the door later. Do you think it is necessary? The battery backup would take care of power outages and what are the chances that two doors would fail at the same time?

Thanks.

IMHO, I would install your side door ASAP. In most places, the building code requires a regular door in such a structure. It is common sense and having only the two garage doors as means of entry/exit, to me, seems like an incredible safety hazard.

You could always use an sds drill and put it onto the wall? that way its more of a permanent solution and looks more professional.