Parents- need advice. When is child ready to be home alone? in My Life...(original..I know!)

I am a high school teacher with a long drive, so I have to be out the door by 6:15 AM. My 10 year-old son doesn’t have to be to school until 8:45, so he gets dropped off at my sis-in-laws house and rides the bus for about 50 minutes as he is the first bus stop. He stopped me dead in my tracks today and asked if he could get on the bus at home in the morning. The thought had never occurred to me! I am actually contemplating it, but I’m afraid someone would think I am crazy and call CPS on me! He is in 5th grade, our only child, responsible, follows rules/directions and would obviously not be using the stove or oven. He has stayed home alone for 1/2 hour or so before and knows emergency numbers, what to do, etc. We have all that covered. I’m just looking for objective thoughts on this. What do you think? Thanks so much!