Answer: Based on your description, I am not certain which plant you have. Boston Ivy (Parthenocissus tricuspidata) and the related Virginia creeper (Parthenocissus virginiana) will turn red in the fall so perhaps you have a different plant altogether. It is possible you have a large leafed form of Hedera helix (English ivy -- an evergreen that can turn brown in harsh winters) or something a bit rarer such as Algerian ivy (Hedera canariensis -- marginally hardy in your area but it is faintly possible in a sheltered location.)
Since you need an exact match, you could root tip cuttings or layer it to propagate it yourself. And, with a very old established vine, you may find that it manages to recover come back on its own from the roots, possibly not until next spring, and regrows very quickly due to the large established root system.
You may also find that you need far fewer plants, as these vines are very large once they mature. You could try to layer it using the existing plant material. Loosen the soil along the base of the wall and work in some organic matter such as compost. Then carefully pull down a few long strands of the vine and lay them out along the base of the wall on top of the loosened soil. Cover the vine with a layer of good quality compost (do not cover the foliage, just the stem) and keep the area moist. With luck, the buried stem will root all along the base of the wall and side shoots will grow up it.
If you want to try propagating it and grow individual plants, here are directions on how to do that.You may need to cut and paste the url into your browser to make it work correctly.
You might also consider layering.
Good luck with your project!
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