I have simulated over 2500 with no human interaction. I'm at the year 2600+ and I stopped pressing any buttons around year 50. I stitched together some population graphs from yesterday:

Infinite: Designing a Town for no human interaction.
As mentioned before, the entire simulation is about keeping the total number of adults at or above the total number of employed workers. Translation: keep the green line above 54. From the graph above, it seems like the green line rare crosses under 100. It also seems like 90 might be a safe estimate at the lowest number of adults.
In the 2500 years I have simulated I know of 2 occurences of my adult population dropping drastically lower than 100.

Infinite: Designing a Town for no human interaction.
I hit 56 adultsthis morning! Screenshot of having only 2 Laborers. That is what I call a fluke year. My town barely survived. Had I failed I would drop the 2 Tailors and 3 Hunters. I believe I would still have enough food to sustain 90 houses but I am not 100% sure.