As to why there should be a difference between the 2 locations... I think you may have hit the nail on the head when you mentioned you were on a different network. Apps such as FaceBook, etc; have data to-ing and fro-ing and also rely on things like location. If your signal is worse than it was before, you would expect some of these apps and services to be continually making a call on Android OS.
Check with your carrier that you have the correct/best APN settings. Try disabling FaceBook, Instagram and Snapchat for a day and see what happens to your Android OS/kernel.