Then you need a VPN solution at each end. I'm no expert on VPNs, but depending on what hardware is running at each end, there is av variety of options. I run ZeroTier, currently, to access my BI machine remotely, you may be able to use it for that, I'm not sure.
There are dedicated wireless, RF, links that will span five miles, or even more. Have a look at the Ubiquity line of equipment for starters if you think that might work out. Both ends would need to be in the "clear", not behind a building or tree, but it is possible to link them that way as well. No ISP involvement that way.