I use LTE modems all the time as backup internet connections. When the main connection goes down, the LTE connection is there to save the day, albeit slower.
A couple of things to be concerned with. First is signal strength at your location. If there's no signal or weak signal, then game over. Second is throughput at that location. Cell carriers will often throttle connections depending on the load the tower is seeing. Back when LTE was new, I was able to get a speed test in the 50 meg down, 20 meg up range. It was awesome. Now, as more people are on it, it's usually more like 5 meg down, 1 meg up. Enough for most uses, but nowhere near the maximum bandwith capabilities.
The other thing you need to make sure you check is your bandwidth limits. Many carriers will throttle you after a certain amount of data usage for the month. You don't want that happening on you mid show!