We don't really have a choice if we want to survive.
Earth will be destroyed when the sun turns into a red giant.
And there are all kinds of other catastrophic events that could wipe out our civilization.
The sun is a medium aged star.
Humans have had their run on planet earth.
Evolution will get us faster than the sun turning into a red giant.
We're a very young species. Our run has barely begun, and we'll likely be the first off this rock. Yes, we will evolve faster than the sun will, but why restrict it to one planet or star system? Our successors will remember us this time, unlike all other species that we are aware of.
Hmm... Humans have been around in the current form for more than 2 million years.
So I wouldn't call our species young.
Plus we seem to be intent on destroying ourselves (and the planet).
With all the radiation we have unleashed, some mutation (and evolution) must already be taking root.