HandBrake (Free, Open Source) Settings for 100MB target:

However, if you are looking for highly compressed content or want to compress your own files to fit this limit, here are the most effective methods and sources: 1. Tools to Create Your Own 100MB Movies

As technology continues to advance, we can expect to see even more efficient compression techniques emerge. With the rise of 5G networks and cloud storage, the need for compressed movies will only continue to grow. In the future, we may see: