Long ferment in a bread machine...Help?

So - long story short, my son called in a panic - they can't buy bread and the stores don't have yeast.  "Could you teach me how to make the beasties?" He has a full time job (from home) and a toddler.  I know he has been using his bread machine to make bread for them, I also know time is limited for fussing with dough.  Here is my best approximation using the constraints of 1. limited time 2. no experience 3. must be a long ferment sourdough. I'd love your opinions about if you think this will work (I don't have a bread machine to test it on) Assume 100% hydration starter.

This makes 2 loaves - cut in half if you only want to make one.

600 g white flour

275g Whole wheat flour

680 g warm water (not hot)

22g salt

225g starter 

1. Feed your starter about 10 hours before you want to bake - I do it before bed.     - remove 75 g of starter add 75g of water and 75 g of flour leave out overnight.  It should be foamy - bubbly in the morning about 9 hours later.
2. mix 600 g of flour and 275g of whole wheat flour and 680g of water together by hand - shaggy looking is perfect - seriously just mix with your literal hand (or finger) Let it sit while you make coffee - about 20mins - 1 hour.
3. add the starter and 22g of salt and mix again - at this point you could dump the whole thing into the kitchenaid and let it do the mixing - or continue on by hand -  mix well - let sit overnight covered in the fridge
4. In the morning, divide in 2 parts.
5. Shape into something basically loaf sized with your hands put into bread pan - ie: bread machine cover with plastic Let it rest about 4 hours
6. Then bake 475 for 50 mins (covered) or whatever your bread machine says for french bread.  If you mix 2 at once one can sit in the fridge while the other bakes.