Yes, you can extend the range with starbases. You can also colonize planets, research techs (some offer passive bonuses), and add life support modules to your ships. All the old trick still seem to work.
However, my philosophy is that if you need things like starbases or life support modules to extend your range, then you are probably fighting a opponent too far away. Adding range modules to your ships will need you to sacrifice some other feature, maybe like firepower or speed. Building starbases runs the risk that they might get blown up, thereby stopping the advance of your fleets.
