50 GB currently isn't a problem for me. Iruka content folder is currently at 4.63 GB and Whitewatt did prune unused assets from it. That just about barely fits into gitlab free leaving very little space for changes.
Git LFS looks promising, but it would mean I would need to self host the files themselves and as such I might as well self host my own repo and keep things simple.
Edit:
I want to give Git LFS a chance, but my concern is that I will end up micromanaging which files goes where. That is time spent that could be used for actual development. If there is a way for Git to automatically dispatch files to the appropriate storage that would go a long way.