Now Rene Heller, in a Scientific American magazine article titled "Better Than Earth," asks whether planets elsewhere may be better homes for life than our Earth. In fact, her article notes that Earth is "poised near the inner edge of the sun's habitable zone and will become too hot to harbor liquid water in some 1.75 billion years." This may sound like a long time, but M and K dwarf stars would have offered habitable zones that could last tens of billions of years.
The article notes that the best time to be on Earth may have been 300 million years ago when Earth was warmer, wetter, and more oxygen-rich. We live on a much less habitable Earth, and it may not get any better. We would be even better on an Earth about twice the size of our current planet since it would have more inner heat, allowing the planet to last longer and benefit from a longer-lasting sun.
Hence, the galaxy offers us many options, some of which may be even better than our current situation. And we still have 1.75 billion years to figure out how to relocate to these new worlds. That should give us a good start.