About 15 years ago I had a job that required me and my guitar to stroll the tables during dinner time. My inventor friend took a cheap cell phone apart and made my guitar wireless; it worked but the sound was terrible.
If they can make guitars and microphones go to the amplifiers wireless, then why not a keyboard? I feel this can be done without replacing equipment. Although buying new is normally the easier way to go. I have a Bluetooth speaker for my IPad, works great.
Just my thoughts, John C.