Since the Starkiller Base is a huge planet, you would think it would be pretty hard to move to get closer to other planets, and it would also need to travel to other stars to actually refuel. But we see in the film that they fire the weapon in what seems like pretty quick succession (say, a few days at least).
The first time was at the Republic, and the second time at the resistance.
Either
the republic base and the resistance base were very close together and there were just more than one star around the base
it has the largest rockets in the universe to move it
it has a HUGE range.
Which one of these is it, and if it's #3, what's its range?