Great post! My answer is mainly for the winter season.

For a winter-ready bag with a focus on sleeping outdoors, consider including a high-quality cold-weather sleeping bag rated for low temperatures, a durable insulated sleeping pad for ground insulation, a compact yet efficient winter tent or shelter, thermal clothing layers, waterproof and windproof outer layers, portable heat source or hand warmers, a reliable headlamp or flashlight, snow goggles or sunglasses, gloves, a multi-tool or knife, and fire-starting materials like waterproof matches or a lighter.