Hi!

You could put them in twelve pots or one or any combo you like. Just make sure there's not too much soil for the roots to handle. Smaller side is better in my opinion. I'd say if all twelve were potted together you still shouldn't need anything more than a six inch pot to start with. Once the roots have grown to the point where there's seemingly more root mass than mix,that's when I'd pot up to an eight inch or so. Take it in baby steps,because too much mix can lead to water logging and smothers roots.

Pothos is a great plant,and grown vertically should in time make for larger and larger leaves which is pretty cool
I'm using a stick I found on a walk by a lake that a beaver left for me. Wrapped vines up it and tied into place with cut cross sections of pantyhose(those things are great for stuff like that).