No, our grandchildren won't live in space, and their grandchildren won't either.

Zero people have ever lived permanently off Earth. Zero people have been born off Earth. 10,000 calories of food have been grown, all lettuce, all from materials brought up from Earth.

Less than 600 people have ever been off Earth, and 99% of them were within 1000km of the Earth's surface.

There aren't going to be magical gains due to "human creativity". We live in a gravitational well. Space is incredibly hostile and almost completely lacking in the resources that we have in abundance on Earth, like oxygen, hydrogen, carbon, and nitrogen.

The idea that we'll be magically living in space in a couple of hundred years is unrealistic.

The last 60 years has shown steady but slow progress in space travel, and the arrival of private entrepreneurs has maybe given us one order of magnitude more efficiency, which given the immense magnitudes of the problem, still puts "man colonizing space" tens or hundreds of quadrillions of dollars and centuries away.

Long, long before that, if we don't direct our attention to the rapidly decaying environment of the spaceship we currently live in, we will experience a population overshoot, and never again be rich enough even to think of space travel.

We need to direct all our available resources to saving the planet we live on, as it is in danger, now, today, this instant!

Ignoring this immediate desperate issue while focusing on completely unrealistic pie-in-the-sky projects that might even be impossible, but certainly take generations to accomplish and not actually fix the problems on Earth, is wildly irresponsible.