Your plan's upload quota is based on uploaded data, not storage. There are no storage limits on MediaZilla. Deleting or replacing videos does not free up storage as storage is unlimited.
Although replacing a video does delete the previous version, each video that is uploaded is transcoded into various resolutions for streaming playback, which is the most resource intensive process.
Learn more about What happens if you use up all your quota before the renewal
Client Delivery Workflow
If you anticipate doing multiple client revisions, we recommend uploading the draft versions in a lower bitrate and/or resolution (3 -5 Mbps in 720p or 1080p). Once the client provides final approval, you can use the replace video feature to easily swap it out with the archival quality version (you do not need to send the client another link).
For the final client version, assuming 1080p, you should set a target bit rate between 10 and 20 Mbps. Click here to see additional information, including recommended bitrates for other resolutions.