One way to reduce your disk space footprint is to remove the planes you don’t use, Tutorials/Flying Lessons, Discovery Flights. Also, if you’re not interested in it, big packages like Top Gun Maverick (which will remove things like the Darkstar etc). This frees up quite a bit of space.
Edited to add: Also remove Bush Trips if they’re not of interest.
One bonus side effect: Your updates over time will go faster, since you can’t predict which of that content will be updated in every World Update or Sim Update. But if it’s not there, the installer skips it.