My first child was a non sleeper & an early riser to boot.
So I was up between 4:30-5:45 and that was then up, awake & on the go all day from that point.
I worked nights.
When my children were small, I had to work all night then stay up all day to look after the child.
I had not much support & nursery/childminder fees were beyond our budget.
I survived on about 3-4 hours sleep a night for the first 5 years of my first child’s life. I was extremely unlucky.
I was unwell, grumpy, exhausted, bad tempered, foggy brained, nausea, felt hungover constantly.
That AND keeping on top of cleaning, laundry , food shopping, cooking & planning meals, getting kids to clubs, to & from school, entertained at half terms & school holidays....does not equate to happiness.
I’m sorry but you are not looking at it realistically, your sleep pattern will not matter one single bit when you have kids, you are on their schedule, it doesn’t matter if you like to sleep until 10am, they need to be up, fed, dressed, at school, etc.
I think you will really struggle... unless you have a brilliant partner to take on the lions share.
Good luck, it’s very tough.