It worked as a stop-gap but I've since replaced it with a GL.Inet X300b ruggedized hotspot without any batteries.

There's no UPS for now... if I went the route of wanting uninterrupted power at the property I'd probably put a battery bank underground outside to power the entire building. It's not worth risking anything rechargeable inside the place given how hot it can get, and how long I sometimes go without visiting.