My sister and I both work in an industry that requires significant and frequent travel – typically Mon-Thurs every week.
I’m currently 4 months with my first so can’t speak to post baby but my sister has a 2.5 yr old.
She returned to work at 6 months (took 2 months unpaid on top of her 4 months paid maternity). She resumed travel as soon as she started back. She pumped and used a milk delivery service to send back home to be bottlefed to her daughter. She continued to breastfeed when home. (so didn’t switch to exclusive pumping).
I think it was hard on her being away for 4 days of the week every week, and wasn’t helped that her project was CRAZY busy so she was working insane hours while gone and so on weekends all she wanted to do was sleep but then also wanted to be with her child/husband.
But I think it was harder on her husband. He effectively became a single dad during the weekdays. He was solely responsible for daycare pick-up/drop off, coverage in times she couldn’t go to daycare, dinners, packing lunches, laundry (they cloth diapered), groceries, on top of general household chores.
After the first month they got a house cleaner, but otherwise he continued to run the household.
He did have my parents nearby so in a real pinch could call them for help – but that was pretty rare occasions.
After ~8 months of this my sister stopped traveling, she said it just wasn’t fair to her husband and she didn’t like missing out on so much.
Honestly I think longer spurts away less frequently may be even harder. At least with Mon-Thurs there was a consistent routine that my brother-in-law got in, it would be even harder having your partner disappear more sporadically and having your workload go from zero to 60 overnight. Plus longer stints away is even more time of separation. My sister said that by Thursday she was just dying to hold my niece again and really struggled not going in to wake her up and snuggle her when she’d get home Thurs nights at like 10 PM.
Most of the upper-level females in our company tend to reposition their careers to be local for a few years while their kids are really young and then resume travel once the kids are a bit older. Also once you hit a certain seniority level the travel is only 2 days a week, so some women put off kids longer until they hit that point as that’s easier to juggle.
ETA: my niece is a pretty solid sleeper and was even when <1 yr old, but even still it was hard on Brother-In-Law to be sole nighttime coverage. The result was that both him and my sister were completely ZONKED on the weekends and too tired to do much. Brother-In-Law also works full time but at a much more stable 40-hr a week job (while my sister’s job can range from 55-80 hrs / week and on that first project back was easily at the top end of that range).
If my sister had been in a cruisier job during the week she probably could have balanced weekends more easily to give Brother-In-Law the break he needed to recharge.