Anyone has any good ideas on how to track network usage on Windows 10? The built-in tool is only good for Windows Apps really.

Parents-in-law have two laptops, on a metered connection while on a road trip, used 3GB in a couple of days. I am told they only use Trade Me, Stuff and Email (Outlook with Google Suite sync app).

They also have Crashplan and Google Drive. Those were 100% synced before leaving (they have a fibre connection at home).

To save some of the mobile WiFi they plugged into a campsite WiFi - 1GB per day. One of the laptops used 100% of this in less than a day. 

Disabled Crashplan and Google Drive. No torrents, presumably no malware (they run as Standard users, have Norton AV installed, MB runs periodically).

Is there anything I can use to track usage? If not previous usage at least something I can install and track that more accurately than Windows does?