Why not unplug the wires from the derailleurs? You might have to cut a zip tie or two, but that's not such a big deal.
I had the same problem when I used to travel with a wired powertap on my Ritchey BAB bike. I had a bag of zip ties that I left in my case (with a finger nail clipper to trim the ends) and replaced them each time I went on the road. Eventually, I solved this by going to a wireless Quarq. But AFAIK, there is no way to make your derailleurs wireless without some serious effort. My concern with putting in a coupler, for me at least, was that I did not know what the resistance issues there might be in mucking about with the cables. There are a few guys on this forum who have soldered their issues away, but a plug and solder can be a different beast. I'm sure it's feasible with the correct plug/connector. Good luck.