I think the end stages really depend on the diagnosis and which nerves are affected. I have no medical background or training but have done a lot of research on my own condition after my neurologist basically said there are no treatments for numbness just let us know if it gets worse.

This basically sums it up... "Is neuropathy life threatening?
Symptoms can range from mild to disabling and are rarely life-threatening. The symptoms depend on the type of nerve fibers affected and the type and severity of damage. Symptoms may develop over days, weeks, or years."
--- Peripheral Neuropathy Fact Sheet: https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Peripheral-Neuropathy-Fact-Sheet