This is the perfect time to kill bindweed. The plant is pulling its resources back to its roots to over winter.
@KentPfeiffer, Kent, you have more experience and knowledge about botany than I do and can understand the "why" of how my experiment worked, but I managed to kill off an invasion of bindweed from my neighbor's garden by just using Round Up in the fall. I have no doubt that it was bindweed.
All I did was take a few soda cans and filled them with concentrated RU and stuck the end of a trailing bindweed vine in it and over a few days saw the vine dye back. Then I did it to a few more vines. I eventually had a field of cans with RU and bindweed vines soaking in them. I allowed each new plant to grow long enough to be able to get it into a can that had RU in it and they all died back. Next spring, none of them came back.
I no longer have bindweed in the garden.
I think by not touching the roots, which I have been told can stimulate new plant growth, if disturbed, the RU was effective, but that is just a lay person's theory.
I've used the same method on poison oak and vinca. I have found it only works in the fall when the plant is pulling its resources back to the roots for winter. I do live in a zone where plants do die back or go dormant during the winter months. I don't know if that makes a difference.