I needed something similar for my RV. I have a Raspberry Pi 3B+ with ArchiveSW - Display & Data Archive Storage running on it. I have setup the RPI with an access point which I then hook the WF Hub to. I added a WiFi dongle which I can pair with my home network when I’m at home or teather to my phone, tablet, or other WiFi source with internet access. I don’t see why you couldn’t just get a cellular modem to install on the RPi. I have a PiJuice HAT for backup power but I found a UPS Pico HV3.0B+ HAT from pimodules.com which I’ll be using for my RV since the advanced version can use an input voltage range of 7-28V. This will save me from a double conversion and I can just run off the 12V system.
I do have an install running on a 2B and it is doing just fine, though you might want to make sure you get an RPi with built in WiFi. I assume that the built-in WiFi is more power efficient.