Just a quick reminder that discs that you burn yourself at home do degrade pretty quickly, much faster than pressed discs. I personally have had burned discs that failed after approx. 6 years. It can happen even faster if you use low-quality discs. Even pressed discs can fail after 20 years if you are unlucky.
Using 2 big HDDs (2 for redundancy) full of your installers might be safer in the long run and also easier to manage and backup.