How does "activation" work?

We are gradually extracting from the X1 team details of how this process works. Sadly, the Help file is mute on the topic of "activation", so we have to guess what might happen in certain circumstances. (There is something on activating, but that only came up when I searched for "Internet", and that item makes no mention of needing regular Internet access after installation.)

How about this one?

I go away for two weeks holiday. What happens when I get home and fire up my PC?

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