Notifications in the middle of the night? That just means you need to OWN your phone and turn off all nite time notifications. I leave my phone on a charger 8 feet across the room from my bed, so it never interferes with sleep. I do allow close family members to wake me up if I need to be notified that a family member has passed or something.
I initially wore my iWatch at night so I could monitor my sleeping pulse rate and have more information about how well and how long I slept. Its battery runs from the time I wake up each morning at 7 am, until the following morning without ever getting half empty; so a loss of wall socket power has no effect on my alarm on my wrist. I put my watch on the charger whlile I eat breakfast and its back to 100%.
My iWatch is no longer cellular enabled - it has cellular components, but I found I never used the watch to communicate by itself, so I turned off my cellular connection for my iWatch and just connect via my iPhone X. I save a few bucks each month and my iWatch battery has less power drain with the local Bluetooth connection with my iPhone.
I also like the ability to use the crown button on my iWatch as a handy volume control on the BlueTooth speaker playing Spotify for me - I find it handy both in bed and while driving.
Different strokes for different folks.
I was a little anxious when I first started using my watch to wake me for sunrise photoshoots which I really didn't want to oversleep for, but after using it for dozens of times, I have high confidence in it to perform properly and to arouse me on time. The vibrations on my wrist are gentle, not jolting me awake, but persistent, in bringing me back to consciousness.