Xbox one won't save offline

You can play your games and they will save you just won't have cloud save access.

https://support.xbox.com/en-US/xbox-one/networking/using-xbox-one-offline

It is possible to save gameplay on both Xbox 360 and Xbox One without Internet access. The only thing that won't happen is your game saves won't be backed up to the Xbox Cloud (on Xbox One) and you can't use the Xbox 360 cloud-saved game storage.

On Xbox One, you will need to make sure your console is set to offline only mode, so it won't try to copy your game save to the cloud. However, there may be some titles that require an online save. Does someone know if NBA 2K18 is one of those games?

Saves are automatically sync'ed between systems, if you buy an xbox one s it would be like playing on an xbox one. You won't notice a difference in how games access save files, plug in the new system and download your profile. Boot up a game and wait while
the game syncs, your save data will then be available offline as well.

Every time you see the sync your system is sync'ing your offline save with your cloud save, and it will work the same on S and Scorpio.

your cars won't save offline, take it online for saving priviliges!

The one way to store your saves Offline is to set your XBOX Console to"Offline" in the network Settings page. With your Console set to "Offline", your saves will be stored on the Built-in HDD or The Drive yout want to have your saves to be put on. There
will be some time when your HDD is full, then you will get a message to free up space .

As soon as you go online again, all your saves will be synced to the cloud.

But be aware even if you will mangae to get all your games saved to an external Drive, you won't be able to access them.