Overlapping Box Reflection issues

I have this house that has many mirrors on walls in many adjoining rooms.

To make these mirrors look right, I have put in many box reflection captures, but this has caused the following to happen to my floor:

What can I do to remove these kinds of over lapping reflections?

How big are these mirrors? Could you just put a box reflection right in front of the mirror?

I did, but because these mirrors are right on the wall, the boxes have to extend right to the other side of room, otherwise the reflection would look weird.
And since capture is done at the centre of the box, I have no choice but to have it extend out past the wall the mirror is on.