Do what you can. Don't want a heat stroke! Breaking the miles up during the day is fine. There was an older lady in my neighborhood who was very overweight. At first, she could only walk to the end of her street and back. Finally one day she made it around the block. Eventually, she was walking several miles a day. The weight came off, and I noticed she was much younger than I had originally thought. . She was an inspiration to others, and I noticed other neighbors started walking around the block several times, too.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!