WP Smush pro + Humming Bird is an incredible help. I have had to buy plugins from Shady companies that did not work as advertised. It's pretty helpful.
However, I am running out of space. Smushing or not, the only choice is to move existing images and future media to something like Amazon S3. Solve this problem once and for all. Its a must have for large sites or multisite. Essentially you have not solved the problem that we are stuck with a single node with limited disk forever.
What are our options with existing plugins?
Can we get something like this? https://wordpress.org/plugins/amazon-s3-and-cloudfront/
For sure I don't want to go elsewhere to buy themes and plugins anymore so I want to know if within your ecosystem, there is any stop-gap at the very least.