A single 4g connection, Depending on where your a, You would be lucky if you get 5 Mbps. Let alone a sustainable 5. And with 3g you would be lucky to get a sustain 1-2 Mbps.
You could try a 4g, see what you get.
I would expect for streaming, at a decent quality. your probable going to need 2-4 4g modems bonded together.
Teradek makes products to do video streaming using bonded 4g connection. They're intended for 4g video streaming. If you contact them, they can probable tell you what their cheapest option would be.