Game on pause dashboards

This is likely because your Xbox One is set to save power and is reducing power use. When this happens does your TV dim until you return? If so look in:

Settings > Power Settings

Especially around the screen and controller options.

Not good at all, may i suggest you shout 'xbox home' it will pause your game and drop you to the dashboard, you can safely swap your batteries.

Another issue may be the reported time playing. If you're looking at the dashboard for the game, some games show "time played", but it only counts for time actually in game, while not paused, etc. So you could have a game that shows an hour in your dashboard,
but has been used for several hours.

It sounds like you had a problem with the mains power during the night. What probably happened is that the voltage supply to the xbox dipped for a fraction of a second, meaning that the console turned itself off but restarted again due to residual power
in the brick. It happens in my area occasionally due to a shoddy electrical company. The supply to the house occasionally dips and all the running computers/consoles would boot up like I'd just pressed the restart button. Buying a UPS (uninterruptable power
supply) will prevent this from happening in the future. They're units which connect to your wall socket, and have an internal battery which acts as a buffer for any intermittent supply fluctuations. Some can supply power for a few seconds or a few days, depending
on how much you're willing to spend. Talk to your local electronics store and see what they reccomend!

Has the problem happened again since the original post? Also what have you done since then to diagnose what's happening?