Good luck! I checked this custom site where they say 'any size'. 8 feet is the tallest they make, and 5 foot width is widest with that height. You need to see if any custom makers can do that for you. MirrorLot Custom Size & Custom Frame Mirrors

'Fab Glass and Mirror' will do that size - the mirror only - no frame - is $2544.00.

Fab Glass and Mirror

Under no circumstances should a piece of mirror “lean” anywhere. This is a killer. Mirror is nothing more than 1/4” glass with silver on its back. It is not stable unless it is attached to the wall with mirror mastic, golf ball size globs in the recommended coverage. I cannot stress enough that mirror cannot safely lean against a wall, even if it is in a frame. If it slips and falls onto a person, death or disfigurement will be the result. And the price of $2544.00 is nonsense. You cannot ship that mirror without crating it unless you have a glass truck. A good glass company can give you a real and reasonable price on furnishing and installing with mirror mastic to your wall.