10000 years is a long, long time. Civilization has only been around for 3-4k years. We shouldn't bother planning further than 1000 years ahead, it's too hard to imagine. Realistically, humanity is awful at planning further than 100 years. Even the most critical infrastructure is built with a lifespan of about 50-100 years and needs to be refurbished.

In 100 years at a 2% growth rate we'd have to grow the economy about 7x.

This seems quite do-able. We would need significant technological advancement but this seems to be happening; there is no technological ceiling. We do not need to colonize space to achieve this, even though it would be nice to colonize space and give us another few hundred years of runway.

There's no reason to assume we can't maintain 2% global growth for the duration of our lifetimes. Whatever is after that we'll have to leave for future generations. Sustainability is important. Controlling climate change is important. I expect the world will look quite different in 100 years and at some point we must trust in the future generations.