My son is 3.5 now. Daughter is 10, in school full time, and easy, so we'll just focus on my son. Not to be a horror-story mom, but he didn't sleep for over 2 years. No napping, inconsistent nights. I was getting 45 - 90 minute bursts of sleep and trying to keep my shit together. I couldn't, and combined with some surgery that went south in recovery, those years nearly killed me. If I could go back and do it again, I would be far more gentle on myself about how much I was trying to accomplish in that situation. That said, I was friendly with a mom who said things like, "Well, I better go wake my daughter up now - her nap is going on 3 hours and if I don't wake her, she won't sleep her 12 hours tonight!" and I would hear this and nearly choke with envy. So kids come in different little packages - some are just way more accommodating to the rest of the family life and some need the family life to accommodate them. I think in your situation, if your husband keeps his flexible job, and you get one of the "easy babies" you might very well be able to work from home during nap time, etc. But you probably won't know until after the baby is born. Being a work-at-home parent can be challenging. (But then, isn't every variation on parenting challenging in it's own way?) Good luck!
Edit to Add:
I occasionally have to travel and often have deadlines that require a ton of work in a short period of time, or appointments that can't easily be moved.
^^^ This kind of thing would absolutely require supplemental childcare, like a nanny or flexible daycare situation. Sounds like the rewards of the job pre-child may not be worth the demands post-child. Good luck!