Sync some folders between nextcloud at home and nextcloud in the internet

Dear all,

I have the following use case.
My internet connection here is really slow, so I have a nextcloud installation on my local network which is also available via the internet.
All clients in the local network are accessing the local nextcloud installation.

Some clients are working outside the local network and they need from time to time to sync for big files, where the sync can take 10-14 days to finish.

My idea is now to setup a second nextcloud installation in the “internet” so I can quickly sync files to it and nextcloud should then take care to sync them to my local nextcloud instance (if it takes 2 weeks, that is not a problem for me). The sync should be a two way sync.
So if I add in my local network (into the folders that should be synced) files/directories they should be synced to the internet nextcloud instance.
But if I upload files/directories to the internet nextcloud instance they should also be synced back to the local instance.

Is such a setup with nextcloud possible and if yes, could you please point me into the right direction?