I also don't really remember having either frequent or extremely larger updates very often on any of the games I've played, although I guess I might just happen to play games that are on the lower end of update density. I don't want to dismiss your experience out of hand, but.how long had it been since you last turned it on? When I play my Switch regularly, I don't ever turn it off all the way putting it to sleep (either by pressing the power button in handheld mode, not long-pressing it, or by holding the Home button on my controller and selecting the option to put it to sleep in docked mode) doesn't lose much power overnight even when it's not on a charger in my experience.
