There is really no practical limit to how long humans can actually live

In the past many people said, "People won't ever live much passed 100". However, scientists are beginning to agree that 142 is the present limit for a human being with present technology.

However, that is subject to change as well and whatever limit is next will be subject to change as well. And on and on into however long people live here on earth or even after we move to other planets.

Actually, the biggest obstacle really to moving to other planets likely is all adults become sterilized (cannot have babies) within the first day in space. This is why Astronauts have always been chosen from people who have either already had whatever children they want or have chosen not to have children or who couldn't have children. However, once you go into space you aren't going to be having any more children. You can have sex but not children after going into space.

Could this change? Of course. But a way to block genetically harmful Cosmic rays and others would need to be created (possibly a lead lined inner liner might do it or something else like this. I don't know for sure.

Or transportation would have to be instantaneously so genetics wouldn't be damaged and make people infertile. It isn't that people can't have sex after going into space. They just can't have babies anymore.

But, as long as we don't stay without a magnetosphere too long the next 1000 or 10,000 year in the polar shift or geomagnetic excursion (whichever one scientists decide is actually happening) within the next 100 years some of us still should be able to have kids ongoing.