Shower caps, toilet bags - I think there might be a theme emerging here.
I usually carry my rig [in bubble-wrap] inside a large transparent toilet bag. If I didn’t take a tarp and it rains unexpectedly, the toilet bag also serves as a rig shelter whilst I’m QRV.
I run the cables for headphones and [Palm] paddles out through the slightly-open zip. Why don’t the paddles get wet? I use a 2m-long cable so I can key them inside my winter jacket pocket with them on a small steel plate. It doesn’t take long to master ‘pocket paddling’.
If it’s not raining too hard, I open the zip wider and use the KX2 paddles.