Hi OP
Firstly congrats on securing an interview after a number of years out of the workplace. From reading this board I know it isn't easy.
As somebody external to your situ...could I ask? Can DH really not do any more than 1 pick up a month?
I just recall a guest blog on MN a while back (cannot link easily as on the app) which suggested that the drive for equality was being hampered by the unwillingness of men to be seen asking for flexibility at work as they were worried about the impact on their careers.
I also wonder how life will be for you with 3 DC, a new job and having to do all the childcare/school runs - I assume.
9 years is a long time for yr DH and his employers to get used to him not having to worry about childcare issues.
However, if you want to re-start yr career, it would be helpful (for you & your employer) if he is able to play a more active role....
Sorry I don't mean to sound preachy, I just wanted to probe if there was really no way for you to gain more support.
Things are not perfect for me
but DH and I share the childcare runs. He works for one of the big 4 etc.
On to your actual question. I would go to the interview - it will be useful practice if nothing else.
Re help. You will be amazed at what people are out there looking for 'quirky' hours. I generally find if you are willing to pay there is a solution. Gumtree could be a good place.
Best of luck at the interview.