Wifi Disconnect Problem

I have an iPhone 5s. It's just about 2 years old now.

My father is an IT. He has set our home wifi to be hidden completely and has set the password to a 63-64 digit random code that only HE knows.

My phone has disconnected from it before when I am in a low level wifi area or when my bandwidth is being sucked up by someone streaming something in the other room. Usually when it disconnects, and the wifi symbol is gone and it just says "T-Mobile LTE", I have learned to immediately hit the power button. About 5-6 seconds later, I'll turn it back on and I'll still be connected again. This, however, hasn't always worked and there are a few occasions when it will disconnect me permanently and my dad will have to manually reconnect me.

As of two days ago, shortly after upgrading to IOS 10, my phone is now disconnecting me when I'm not even using my phone. For instance, last night, I was watching a video, got tired, put my phone to sleep, and woke up with no wifi. This has never happened to me before ever. I do not have a data plan on my phone and it is currently not possible to get one so my only source of internet is our home wifi.

My dad had said that a factory reset would probably do it justice and fix the problem, but instead we decided to reset the network settings in my phone yesterday. That, obviously didn't work as I have no internet right now.

What can I do to fix this? It is NOT possible for him to shorten or give me the password to the wifi, he refuses out of concern for security, I suppose. So is there a way I can just remain connected and not have my iPhone forget the network?

Please feel free to ask any further question that may help your endeavor into fixing this issue. Thank you, Andrue Stone.