You identify a difficult problem. The combination of distance and
intervening noise on how your hearing aids work is a problem in theater.
I suggest you and your audiologist work on some remote system. There are
personal infra red systems with built in amplification and/or adaptability
to be used with your own hearing aids. Each theater has an infra red
system if they are using their assistive listening devices. It may be
expensive but its worth exploring with your audiologist. You could then
ask each theater to situate your transmitter near theirs or, perhaps your
receiver could work with their transmitter. For those live theaters where
the actors are miked, you could use a remote FM system and ask for it to
be attached to their transmitter system. Good luck.