As mentioned above, if you get the parking lot seal coated, then all minor cracks will be filled in. However, larger cracks/potholes require different treatment. If you decide against sealcoating the lot, you’ll still want to have all existing cracks sealed before winter, for sure.
Cracks allows for water to get deep-down below the asphalt surface. Once this happens, the water then freezes and expands. Come spring, that water fully melts demolishes the subsurface, which results in severe breakage that can turn into potholes.