Sennheiser MM550X sounds like the right item for the headphone end, just need to find a reliable sending unit, and that may be the issue.

But, I do believe that distance can be a serious issue with BT.




Anyway to send the audio signal to a bedside table, or whatnot, where the sending unit/charging base and the headphones could reside.

Seems like that would be the easiest way to make this work reliably.