Definitely something that my wife and I struggle with. She's Vietnamese British, I'm Vietnamese American ; both of us current living in the U.S. Despite what our training classes recommend, we're co-sleeping with our 17 month year old daughter and it feels more intuitive.
So - if you don't mind the question, sorry for asking if you do - how/when you have sex?
Our sex life has probably never been better in either frequency or quality.
We typically do it in the living room on the couch in the morning before they get up, or same location during their naps, or in my work-from-home office also during naps. Or where-ever we want when we have a baby sitter, although with the pandemic that's pretty rare.
I'd say about 75%-80% of our sexual activity is essentially scheduled at least 4-6 hours in advance, sometimes more. This works great for all involved. Occasionally if we miss our window because one of them wakes up early, we just reschedule to the next soonest window. We'll occasionally even stay up late after we put the boys down to makeup a missed session.
I also think breaking the habit of only having sex in our bed at a particular time when one or the other kind of vaguely expects it is a big contributor to the improvement in our sex life.
Instead we have explicit communication about when and where we're going to have sex. There's still some room to be spontaneous, but it's very limited with kids.