"I need portability. Whatever solution I arrive at will have to fit inside my bike's frame bag."
Then, as one solution suggestion - go to your local Home Depot/Lowes, they sell hollow aluminum tubes that are used for towel racks and stuff - pretty light and pretty cheap. Buy as many as you need for the height, glue in some sleeves so that you can put them together, and you have a pole.
Also, I might have some carbon fiber rods that could work that I got from Josh some time back that I no longer use. If I can find them and if they're stout enough, I'll ship them your way.