[jewel]

It depends on the bitrate. Let's assume 10 mbps for five cameras. That'd be 16.4 TB for a month's footage.

Depending on the application, you could lower the bitrate significantly during times of low motion or low detail (such as at night). You could also drop the framerate.

I've found that when the scene is static, without panning, and no wind blowing leaves on trees, you can compress really well. I have a Wyze outdoor cam looking at the front yard that does 1080p at a little less than 1 mbps.