While writing out a more detailed description of the behavior, I stumbled upon the solution myself.
When you try to install the game over the internet, just let it start, and then cancel it. This will both remove the installation and download from the queue, but apparently also remove the knowledge of the installation from the Xbox One.
So:
- Start the online install
- Cancel it
- Return to the home screen
- Notice that the disc tile has now changed to "Install disc"
- Activate the disc tile to start the installation from the disc.
This worked, the game now installs from the disc. Obviously any downloaded DLC's will still need to be downloaded, but for the purpose of this question this is not relevant.
Now, what do you do when you get back home and want to plug in the external drive?
Here's what I did. I first uninstalled the game using the storage management.
This makes my Xbox One forget that I had the game installed. Make sure you don't delete any savegames you have on the console.
Then, you turn off the Xbox One, plug in the external drive, and turn it back on.
Once you do that, the disc tile still says "Install disc". Ignore that. Instead either use your pinned link to the game, the tile for the game (if it shows up on the home screen), or navigate to your games and apps list and activate it. You should get a message saying not to unplug the external drive, and that your game will be ready soon.
A few seconds later you can try again and the game should now start.
Best Answer
I can't speak to FIFA specifically, but these types of accounts are used by publishers to promote their own communities, distribution platforms (Origin, for EA), and subscription services (EA Access). The legal text is just your standard End User License Agreement, the same kind you checked a box for when signing up for an account here. On their own, the worst they'll do is send you emails advertising new games or sales.
With just an EA Account you shouldn't be charged for anything you don't explicitly sign up for, so if you don't want EA Access (which is a subscription charge), just don't sign up for that. You can make sure this doesn't happen just by not giving it your card information at all, which will make it will prompt you for the info if you accidentally try to buy something, giving you the opportunity to back out.