Howdy,
I've been monitoring my off-grid system, remotely using cellular, for years.
On the MidNite Forum checkout the sections 'Raspberry Pi' and 'Node Red'.
Your will need a MidNite Classic, an ethernet cable, a Raspberry Pi, and some sort of cellular or starlink interface.
Thru the years I've used my cellphone's hotspot, a cell modem and finally the T-Mobile Home Internet router.
Enjoy....