Seems to me the answer is that any planetary evolved creatures (and there's no evidence that life can evolve anywhere but a planet) would have to achieve god-like powers to cross the distances of interstellar space, even at sub-light-speeds.

Simply leaving the gravity well demands uncommon control over biological and physical conditions, to the degree that any creature capable of doing so has an equivalent god-like status over every other biological creature on the planet. Getting to nearby planets and surviving and making it back demands a thousand-fold more authority.

To cross the distances between stars means that any biologically evolved creature would need to have absolute control over its own form and mind as well as every aspect of the physical container in which it travels. Between the coldness of space, the absence of any resources, and the effects of containment on our biologically-evolved minds, planetary-evolved life simply lacks the ability to survive the journey. It's hard to overstate the implications of this control, which include eveything from near enough immortality to a perhaps impossible understanding of our own mental processes to the ability to control matter at the atomic level.

There's an aspect to this that's similar to our inability to grasp the implications and effects in the differences between large and much larger numbers. For example, a million dollars in $100 bills is a stack about 3 1/2 feet high. A billion? Nearly a kilometer. That kind of scale changes everything. In simple physical terms it changes the gravity of the thing, and its relationship with everything around it. In monetary terms it's makes billionaires godlike creatures within the world of money. And a trillion is to a billion as that billion is to a million. The distances between planets and their moons, planets and each other, and stars to each other is a similar scale.

Getting to the moon is like having the power of a million dollars. Getting to the nearest planet is the power of a billion. Getting to the nearest star requires the unimaginable power and scale of trillions.

I don't think we are capable in our current gravity and biology chained forms of in any way understanding what kinds of beings we might become when we achieve the kind of power needed to cross interstellar space.