This is one thing that I think is underestimated: just how big of a hurdle it is to travel between solar systems. It took the Voyager probes almost 40 years to leave our solar system, which is like taking 40 years to get out your front door on your planned walk across all of Europe and Asia.
By the time we have the technology to do so, we will necessarily have the technology that makes it unnecessary. The primary thing you need is something that can survive effectively indefinitely in deep space where there are no resources available. But if you have that you can build stellar colonies that have unlimited access to solar power and can survive indefinitely just as easily.
It's not like we are short on mass in the solar system either. It will be a long long time until we've used up Jupiter, Saturn, Uranus, the belt, etc...
By the time we have the technology to do so, we will necessarily have the technology that makes it unnecessary. The primary thing you need is something that can survive effectively indefinitely in deep space where there are no resources available. But if you have that you can build stellar colonies that have unlimited access to solar power and can survive indefinitely just as easily.
It's not like we are short on mass in the solar system either. It will be a long long time until we've used up Jupiter, Saturn, Uranus, the belt, etc...