I have Xfinity now, so uploads are pretty good (300/80), but I used to have Spectrum, which not only cost more but only got about 8 mbps up. My solution was to restrict clients to low bandwidth streams, like 3mbps. I only had a couple users, though, so obviously there’s a limit to how far that will scale.

If you can’t upgrade or switch providers to increase bandwidth nor throttle clients, I think the only other solution would be time restrictions, but it’s really going to depend on your users whether that’s effective.