How many hours is too many?

This is purely hypothetical, but how many hours would you be willing to work, and what would you charge for longer days?

Thats essentially my question, I'm adding more details below, but feel free to just answer that bit if tou dont want to read it all

My baby isn't born yet, but the daycare situation in my town is a bit sketchy and it can sometimes be a year or two on wait lists before you get in, so im thinking about my options now so I can plan.

I was a nanny, and at times an au pair living in the house with the families when I was overseas, so I am considering this as an option, but I currently work long hours so am not sure how it would work. I was a bit of a push-over when I was younger so I tended to accept longer hours and less than amazing conditions just for a job, and i dont want to do that to anyone, so want to plan for it now whipe im still just me. I am open to live-in, if that changes things.

I obviously don't know what my schedule will be like when I do return to work- whether it will be full time, part time, hybrid WFH, or something like that, but I currently work a standard 40hr week, with up to 10-15 hours of overtime when its busy. I doubt I will work that much when I return to work post-baby, but am trying to gauge whether thats even an option. Ideally I'd have bub in daycare and just need care for the few hours or so in the mornings or evenings, but I don't know what the situation will be yet.

I generally work 7am-5/5.30pm Mon-Fri and occasionally 8-12 on Sat, but even if I just work my base time, its still 45hrs a week I would need care, and the daycares are generally only open 8am-4pm, some even close at 1pm, so there's no way I can do my normal hours with just daycare, but also dont know if i can afford full daycare fees AND a nanny. With it being minimum 45hrs for a nanny JUST to cover my working hours, and 55-60hrs if I work full time, thats a lot to ask someone to do. I plan to return to work at 6-9 months, which is right when they start walking and are eating foods and getting attitude, lol, so it'll be hard.

Would you work 60+ hours/week? Should I plan for two nannies, working on different days? Would you accept a role for 2hrs in the mornings and 3 in the afternoons? It may be more if I can't get all of the days at daycare.