Well, I’ll tell you how my DH and I handled it for what it’s worth. I apologize ahead of time for the novel.
For background, my DH and I both worked from home from the time my DD was born until she turned 4. My DH had just started his own business at the time so while his income was more sporadic his work load was heavy. I worked for a company that allowed me to work from home since the job was all computer based. I went back to work at 4 weeks PP because my income was more stable and we really, really needed the money and I had no maternity leave. ( I had to save up several years worth of vacation time just to get those 4 weeks.)
The way it worked out for us was that I did the majority of the childcare during the day since I was nursing all the time and she was so frequently going to need my attention anyway. My DH took care of everything else (cleaning, laundry, grocery shopping, dish washing, etc.), basically everything except for cooking which he had never learned how to do. He also took care of some of the nighttime childcare. For myself, I kept the cooking really simple, easy, basic and only for dinner. Breakfast and lunch were no cooking affairs. Just grab some fruit and a bagel or make a sandwich on your own type of deals.
Our DD was never good at naps. Her naps were always short and she preferred to be touching me in some way so after trying lots of different options/locations to get her to sleep longer and more regularly, I ended up rearranging my desk so that the computer was low to the ground and I just sat on a cushion on the floor so that if she fell asleep nursing (which resulted in the longest naps) she could just continue to sleep on my lap for however long she would and I could continue to work. This arrangement also worked really well when she got older and was crawling around more because I was at her level and she felt like I was right there with her even if I concentrating on computer work. I could never count on nap time for much work production so I had to learn how to get work done when she was awake.
As she got older I had to be pretty strict about not being her playmate. She really had to learn how to keep herself entertained and luckily she took to that really well as long as I restrained myself from playing with her much when work was slow. Otherwise she would expect me to play with her all the time and would have horrible meltdowns when my work heated up again and she expected me to be available to play all the time.
There was no way we could afford any type of childcare or even a mother’s helper which could have helped. The hardest part for me was that I was generally billing 30-40 a week on my job, which when you when you figure in all the childcare time meant that I was working on my job or trying to work on it from the time I got up in the morning to the time I went to bed at night 7 days a week. It would take me 16hours or more to get 8hours of work in and it meant that I didn’t really get any breaks at all even on the weekend since I would frequently need that time to do work I wasn’t able to complete during the week. If I was in the middle of a really tight deadline or was struggling with something especially difficult and I needed help with the childcare (changing diapers, baths, just holding and rocking, whatever) my DH would always make himself available to help out, but since he was starting/running his own business he was also working non-stop 7 days a week trying to get his business off the ground so his availability was limited too.
I also had the further complication of short deadlines and not enjoying my job at all which really added to my stress. Since you are looking to get in closer to 20hours a week with something you love to do, I think it should be a bit easier as long as you can spread that time out over the whole week. Flexibility in your schedule is really key, I think. There were whole days when I wouldn’t be able to get any work done because DD was teething or sick or going through some sort of developmental stage which would make her super fussy. You can’t predict and plan for those times so you have to get good at rolling with it when they come up.
Somehow we made it work and while it was very hard and stressful, we both cherish having had that time to spend with our DD even if it wasn’t exactly ideal.