Q.Possibly dread philodendron
Took “Phil” outside last summer. Roots are 40 yrs old and never failed. Last summer I had vines 9 feet long, but I may have waited too long to bring him in. This winter, I had only 1vine with 1 leaf. Now, that seems to have died. Any rescue?????

I don't think your plant will come back if all green stems and leaves have died.
Treat yourself to a new plant.
https://www.gardeningknowhow.com/houseplants/philodendron/caring-for-philodendrons.htm