Even if we accept that life-extending and rejuvenating technologies will progress as described, and that all diseases will eventually be either curable or eradicated, there's still the risk of death from accident (or murder).
In England and Wales in 2010, about 0.025% of the population died from accidental or malicious (but not self-inflicted) injury or poisoning. If we take that as a typical annual risk of death, then over a thousand years you have a 22% chance of dying from one of those causes. At about 3000 years, it becomes more likely than not: at about 9000 years, overwhelmingly more likely (~90% chance of death); at about 50000, a practical certainty (> 99.999%).
Of course, the above assumes that risk of death from injury won't drop as medical technologies improve, which is wrong, but as long as it's non-zero, there is still going to be a statistical limit on the length of life. No hanging around till the heat death of the universe for you.