Our astronomy club has a small observatory shed in a rural area with no wired connectivity. Solar panel and marine battery are there for limited power. There is data coverage by 'Verizon'. What is the best way to have an RPI 24/7 active at the shed with USB 4G modem (recommendations?). The goal is to have ssh from remote home computers into the RPI and get some weather / sensor / security info. Obviously data volume is an issue. What's the best deal? Pay-as-you-go? I've read somewhere that RPI OS when left to itself had depleted the monthly data volume on USB modem within minutes just doing it's own administrative stuff. What special setup/config needs to be done on the RPI to make it 100% quiet when alone and only respond to user ssh logins from outside? Who has done stuff like this?