Turn off watch WiFi

Our daughter is working at home now. She needs all the bandwidth she can get. We have been shutting off WiFi overnight on as many devices as we can do she can be the first to log on (we read that the first to log on gets the best signal). Control center doesn’t work for the iPhones nor iPads (because that causes them to reconnect at 5:00am and none of us is up then!) but switching it off in Settings works on those devices. However, my Apple Watch 4 will not stay disconnected to WiFi. So far I’ve tried and failed with 1. Control center (swipe up, touch WiFi button—same 5:00 problem I presume), 2. Shutting off the watch entirely using the side button and then putting it on the charger (watch and WiFi were on at 9am).

Can I change the 5am start time to a time of my own choosing? Do I have to shut it down and NOT charge it? Other suggestions?