I timed it today with the stopwatch on my phone... 27 minutes, including kid help.
4pm: Wash and dry the bowl and then mix up the dough. 264g water, 9g salt, 98g sourdough starter, 418g flour (half bread flour, half all-purpose), mixed with a spoon and then by hand to incorporate all the flour, wash hands:
11 minutes
4:30pm: I put the dough on a clean, damp counter to stretch it. Clean the counter, sprinkle water on the counter, take the dough out of the bowl to stretch/knead it, put it back in the bowl and clean the counter again:
1.5 minutes
6:30pm: While cleaning up after dinner, I clean the counter and stretch the dough, put it back in the bowl and clean the counter again:
2 minutes
7:45pm: Last stretch before it goes in the 'basket' (I use a bread pan with a tea towel) to proof. I had help from the 10 and 2-yo for this step, so it probably took a little longer than if I did it all myself, but the upside is I finished filling the dishwasher and started a load of laundry while they 'worked'...
...clean the counter, dust it with a 1/2 TBSP of flour, stretch the dough, roll it to shape, place in the tea towel in the bread pan, clean the counter again:
9 minutes
9:15pm: After the dough sits out for an hour or so, I walk it to the refrigerator to finish proofing overnight, then clean up the flour I didn't realize the toddler dribbled down the front of the cabinet and onto the floor.
Next I feed the starter for tomorrow, which is 55g whole wheat flour + 55g water, then stir:
3.5 minutes