Upload via wifi.
I think there should be an option that you can select like "upload via wifi" which will queue up items but wait until you are connected at a wifi network before uploading files. This would help reduce mobile data usage.
I have been trying to make the OneDrive support team understand my issue through OneDrive: Help ticket #30099-845493.
The Camera Upload/Backup feature has the necessary options to upload via WiFi only or Mobile + WiFi.
But what if you're manually trying to upload files to folders? Since there is no such option, it uses whatever internet connection it finds. I had to go completely offline from morning till I returned back from office in the evening to resume the upload over my home wifi.
If there was a simple PAUSE or Upload via WiFi option for files it would have been a blessing.