The customer's main office has a simple setup with a generic router from their ISP and a PC with their shared files in a shared folder, plus they have two PCs on their LAN that can access that share, all networked together via Cat6 cable. A standard simple setup.
Now they are adding a PC at a remote office 20 miles away, and they need that remote PC to be able to map a drive letter and access that share just as though it were on the LAN in the main office. Note that this remote PC does NOT need fast speeds, and actually there will be very little network traffic, but it does need to stay connected reliably.
Years ago I had a similar situation and I used LogMeIn Hamachi, which did exactly what I've outlined above. But it was slow and clunky and unreliable, often disconnecting at random times and difficult to reconnect.
Is there a good solution these days that is relatively simple and moderate cost that meets these needs? TIA