Here some leftist instances, uploading is allowed on some & disallowed on others, although you may be able to request an exception depending on your content, but their network can be helpful, another tip use Sepia as a Peertube indexers to find more.
https://tube.doortofreedom.org/about/follows
https://peertube.red/videos/recently-added?s=1
Edit:
I need to put a pin on this for now.