I was in a similar situation to you op.
I now have a two year old and a 6 year old and I childmind two days per week. The other days I go out to work.
We couldn't afford for me to work full time due to the child care costs, but equally couldn't afford for me to just work part time. Childminding seemed a good solution given that I already work within a child care setting.
It has worked out well for us as a family. I look after 4 children from two families - I decided that I would not look after children under 3 due to my own children's ages, though I am registered to look after babies from 6 months.
The pros of childminding is I am able to be at home two days per week so can drop off and pick up dd1 from school. Dd2 has been able to start a local play group too because I am around to take her and able to be a helper every 4 weeks or so. My youngest mindee is in preschool in the morning so I do still have time with dd2 and can still meet friends for coffees etc.
Being at home two days means that I am still able to keep on top of washing etc. I can find the time in the day to do this. My house is not a disaster because we have tidy up time after dinner, just before everyone is collected. Then as soon as the kids leave I give the house a quick Hoover and clean the loo etc.
I am not insured to care for the children unpstairs so they stay downstairs. I have a downstairs toilet. I prefer it this way and I know most childminders are the same.
A bigger car is a good idea. We have a 7 seater now.
The cons - you really don't get a lot of time with your own kids though you are physically there so they probably feel the benefit more than I do. Dd1 has a dance class after school on one of the days I childmind and we have managed to keep going to it but it is hugely stressful. I drop her off and then take the other kids to the park or library but I find it all a rush and am tempted to give the class up, though feel bad about that.