It depends upon the conditions under which you put on the miles you do. Suppose every time you drive it, you only go a couple miles. That is not long enough to warm up the engine, have it run lean, and have the oil heat up to cook off moisture. This is even more true in a Michigan winter where you might have to drive quite a while to get the oil up to temperature.
50 trips in this state is much harder on oil than 1, 50 mile trip. It also means starting the engine an additional 49 times, supposedly when engine wear most often occurs and where do these wear particles end up? Either as deformation or more often in the oil.
No it does not need changed every 6 months in "most" cases, but if you were to drive a mile a day every day, "maybe" it needs changed on a yearly schedule.
More to the point, if I were you with low miles, what I would do is "sneak" in an additional oil change between each of the dealer free 7K oil changes. Maybe use the same filter brand so they don't catch on (or don't, that shouldn't really change anything). Don't reset the oil change indicator if the vehicle is so equipped.
It may not be the perfect interval but it seems to make the most sense and still take advantage of the free oil changes.