I have an off grid space that I work from. For connectivity, I use a 5G phone on T-mobile with the EasyTether app (which tethers over USB and doesn't count as hotspot data). I have an RPi connected to the phone and a travel wifi router connected to the RPi over ethernet.
That said, 5G service is pretty good in my location, speeds are fine, but isn't the cheapest solution ($70/mo.