Fresh parents without relatives to help out.
We still managed fine. All young kids sleep quite a lot. Newborns a crapton. Older kids who don't are old enough to sauna too.
Check out the screen time log for fresh parents.
I remember the first few months being so crazy. Feedings every two hours, and each feeding took an hour.
But still time for naps, short walks, etc. part of the survival was to work in little microbreaks when the baby was sleeping.
If it's winter, put the baby in the pram outside, while you do a quick sauna session?