I've been skeptical of using cellular as a backup solution, cost being the primary concern. Cellular data is not exactly cheap. Yet I found myself in a situation recently where I was working from and had a remote cutover. Less than an hour before the cutover, my home internet went down. Now posed with the option of either driving into the office, or finding another internet connection with less than an hour.
I grabbed my IBR1100 that @Cradlepoint gave me from #WFD8. I pulled the SIM out of my work cell phone and 3D printed an adapter in order to get my SIM into the router. One I powered the IBR1100 up, it came up and I logged into the interface for the first time. The interface is simple, the initial setup wizard asks a lot of the right questions to get the device up and running quickly for most of their primary use cases.