I'd say to still use a VPN like openvpn, I'm not 100% sure but this seems to be one that works with a pi. @ zac123 I would check openvpn's website to see if they have any links to do this as well (do your due diligence)
https://www.ovpn.com/en/guides/raspberry-pi-raspbianhttps://www.comparitech.com/vpn/what-is-a-vnc-and-how-does-it-differ-from-a-vpn/As for 4g it's not great but you can only use what's available. For only 1 machine/connection it should be just fine, the avalons don't do much in the way of connections like the s9's do they do a dns query to resolve the pool then stay there for a while, bandwidth is limited on them on 24 851's on 1 pi they top off at around 15kbs but average 10-12.
If you have a bunch of miners a simple dns forwarder / cache server would work to limit the outbound requests, it won't do anything for the work the miners need to process.