In USA, Sears and J.C. Penney have large nursing bras.
Also, I find many women in this size range discoverer the
stretchy "sleep" or "exercise" bras are very comfortable.
Instead of fussing with hooks one need only pull up the entire
cup.

Your local maternity shops may have information.

There are several bra companies that run custom sizes--very
small to very large. I don't have a long list--but will be glad to
pass on info by private email. Let me know.