How long can you live with graves disease without being treated?

That depends: Really hard to answer. But thyroid storm is a complication which can occur under stressful circumstances like other illness and when graves untreated and is life threatening. Chronic uncontrolled graves will cause osteopenia, possibly cardiac arrhythmias, maybe liver trouble, and will likely only get worse without treatment. No cure for graves except ablation or surgery. Antithyroid rx temporary.