This (https://hologram.io/nova/) website lead me to the ublox SARA modules.

I think I'll be using a celluar data module like this one (https://www.u-blox.com/en/product/sara-u2-series) in my design. I think it will necessitate another ACIA serial chip.

As far as I can tell, the ublox chips can interface via UART, and recieve AT commands. There are modules that do LTE and positioning as well.