With adequate access to natural light, it's pretty hard to oversleep if you follow your body's natural schedule. As soon as light hits your (still closed) eyes, your brain scales back melotonin production and raises your body's temperature, which is what wakes you up. The opposite happens when the sun goes down and you aren't around artificial light.
Given how vastly different lengths the night have depending on how far North/South you go, that might be so but it's a solution that won't for for a whole lot of people without artificially simulating a shorter night.
