I have a question concerning configuring LTE mobile internet services and devices to integrate with a LAN to circumvent the absence of broadband in a rural area.

I have a laptop that runs as a headless server. It is configured to have a static IP address, to run as a DNS server, A Media Center and as a DHCP server using dnsmasq while the modem/router hybrid is given to me by my ISP currently running only as a Gateway for internet service to flow through this LAN and serves as a b/g/n hotspot for wireless devices to connect to it. The laptop and all other wired devices(Samsung Smart TV,Ethernet Bridge etc.) are connected via ethernet cables to the router so that it receives internet service for security/software updates etc. Now a new problem arises where I will have to move into the countryside where the broadband service that my ISP provides through the modem/router hybrid(It's an Arris 5 Ghz Router) will not be available and only mobile internet data is available. I considered trying to use a Mifi Device but it does not have ethernet ports and does not function as a router would, only as a hotspot for wireless devices which would leave out hardware that are configured to accept only wired network connectivity. What strategy or combination of hardware/software you would use to solve this problem so that internet service will be available to both wired and wireless devices in the LAN using mobile internet data provided by your mobile carrier through a USB Dongle or a Mifi Device?