For remote access and editing of files we use Syncthing, Its free and works very good, data is also encrypted. We store any data on LUKS encrypted disks also.
We have a few businesses using it and it just works for them. No port forwarding needed as it uses nodes over the internet to connect endpoints.
Syncthing is pretty cool. At my previous employer I was almost done a project to use syncthing and salt to create a drop-in replacement for redirected folders+ offline files.
I would be looking at NextCloud first now though.