MrClass wroteThat's not going to help. Whatever is consuming 50GB in (let's say) 10 days, will still consume 50GB in 20 days. Make a caching server, or block all traffic from going through and just let through the apps you want to have connected to internet.
Windows updates, game updates; ADs in web browsing, will all consume quota. Watch videos in 720P instead of 1080P. Tell your web browser to stop autoplaying videos when loading sites.
Enjoy your 40Mbps man; the point is to move forward not backwards.
Similar to the idea of upgrading your computer every 5 years cause it gets slower; your Internet needs an upgrade so you catch up with the rest of the world.
Not exactly like that.
For example, if you limit many video streaming apps speeds - they will switch to lower quality. So watching same movie will take less traffic, but sure quality will be worse.