By the time the sun starts going into its death throes, we will have evolved into something not quite us in a mere 50 thousand years. I'd worry about the implications of that first.
I don't think most people consider the time involved. It's "only" been about half a billion years that there has been multi-cellular life on the planet, but we're talking ten times that when the sun goes. I hope there will be something that develops from us and isn't limited to one planet in five billion years, but I would be quite surprised if there were still recognizable humans. It's possible our machines (with an AI capability we can't imagine) might be the future heirs of our civilization and wouldn't have a lot of our frailties and limitations when it comes to existing in space.
But then an asteroid might come along at anytime and render the whole argument moot.
