With the no-walls and sell-everything-for-tech strat, your people will frequently pass away from hunger, direct exposure, and Iron-age raiders (do not stress, its worth it for optimisation). Ensure you have a lot of houses offered to stock people in case this takes place. Constantly attempt to have at least 4 real estate slots offered. With that stated, monitor your food levels using the food UI. You have plenty of food to expand your population if you're regularly in surplus each season. If you're frequently running out throughout Winter, expand your food production. If you do build walls, ensure your stables are inside them. Raiders can target animals inside stables, and will kill them.