Hey Rick, thanks for that info.
And thanks for your patience. I was traveling the last few days, so I've been a little slow to respond.
When streaming over cellular connections, it's usually best to use a bonded connection across at least 2 separate cell modems and cell carriers. This becomes increasingly important in a moving vehicle. If you need absolute uptime and reliability, I would recommend finding a bonding solution. But if you can deal with a few hiccups and possibly lower stream quality, then the setup you currently have will get the job done (assuming LTE service is somewhat consistent throughout the areas the vehicle is traveling).
I don't think you're really over-speccing anything in that setup. The megapixels of the camera aren't going to be as important as other things like encoding quality, bitrate, etc.