definition of plant runner:

A stolon is a horizontal stem that is fleshy or semi-woody and lies
along the top of the ground. A runner is a type of stolon. It is a
specialized stem that grows on the soil surface and forms a new plant at
one or more of its nodes. Strawberry runners are examples of stolons.
Remember, all stems have nodes and buds or leaves.

basically, a runner is the part that starts at the base of the plant,
skims along the ground and roots nearby, starting a new plant. if your
vine is as large as you say, you should have several runners.

even if you only have a *nub* of a root, it should work......

all the runners I have started indoors have been off of broken field
plants. Since yours is in place already, i would pamper it a little and
maybe take one or to runners to re-root separately, in case the original
plant doesn't bounce back.[/quote]

Thank you. That's very helpful. As soon as it stops raining I will go in search of stolons and see what I can recover. I've already given the plants some plant food, but the weather has been so wet, I doubt if it needs any more water!

I am still hoping for a recovery of the old plant, but most of the leaves are now shrivelled up or black. I guess I won't know until spring if there is still some life in the roots.