How long would a person live with hepatitis c if they did not get any treatment at all?

Depends: It all depends on how much liver scarring they already have, how old they are, how long they have had hcv infection, and whether they have any conditions that accelerate scarring like alcohol use or hiv. Men who have had hcv infection for more than 40 years have a 70% chance of cirrhosis. About one third of people with hcv will die from it ( as opposed to all the other things that can get us).