You will not use anywhere near as much as you would think. I was able to play about 3 hours a day for a month on a verizon jetpack 4g lte hotspot and didn't even come close to using my 10 gigs. However, you are going to experience lag at times b/c you are connecting to a cell tower, and also you have no control over the cell companies NAT restrictions.
I plays cod mw remastered online and you will go over. The lagging should stop. I use Verizon unlimited and hotspot off my phone and it works great. Never any issues