Thanks for sharing these thoughts in this article and I can certainly relate being a full remote worker. One thing that has really helped me is keeping an 'office schedule'. I still have the family time in the morning and even walk my kids to school most mornings. I then work all day and "clock off" at 5:30pm. No computer and work related things past that time.
The way I manage this is by reminding myself I work for a business and we have a contract for a set number of hours. Also however much I do there will always be an infinite amount of work more to do. So a few extra hours in the evening makes no sense.
Good luck to you on this journey and like other people have said, the fact you are concerned and thinking about this makes you a great parent already.