The thing is op whatever happens you make it work. As long as your partner has the same attitude in that there will be times when you both have to make sacrifices, then you will just create new solutions for each new phase that comes along, whether you've got 1, 2 or 3 children. I have 3, all still in primary so the baby years are close enough for me to remember. We went through so many phases of different routines, who's picking up this week, who's dropping off, who's on overnight wake ups etc. And then something changes, and HR routine gets tweaked.
Without doubt our hardest period was after i went back to work having had dc3. I had one in school, 2 in nursery (totally separate location to the school), we were both commuting in to the office and dc3 did not sleep through, ever, until she was 3.5yo. I used to quite literally keep myself sane by counting the years months weeks and days until that period was over. You do just cope but i found being very firm with dh from day one that this was a joint effort and insisting it was 50/50 in all areas was the key, because frankly he would have been quite happy for me to have just done it all.
A pp mentioned not wanting to end up having to put kids in after school care etc which i can understand. For us it was the only way to make it work, along with breakfast club, but i knew it would only be for a short time relatively speaking. As they get older they can sort their own breakfast so now they don't go to breakfast club and after school wise, more interesting clubs open up to them as they grow so they actually want to do the gymnastics and cooking classes etc. Everything changes basically and you just have to be able to adapt.
Work wise it certainly helps to have a flexible employer. I'm very lucky, as is dh.