In cold country, you guys need to minimize winter space to make it easier to warm the hive. I dont know the dynamics of the nectar flow in other areas, but here in my area, we have a good flow of wildflowers and sweet clover in may and june. I live near a swamp where we have summer blooming water lilies, water lotus, and a variety of other blooming aquatic plants. Many southerners have a dearth in july, aug, and part of september, then we have an abundance of fall composites and goldenrod. I rob in early july to capitolize on the light honey from the spring flowers and then put the drawn, empty supers immediately back on. The bees will usually fill them again by november, when I remove the supers and rob again. The fall honey, especially if there is a good goldenrod crop, will be darker than the spring honey. If i leave the supers on the hives in the fall, then when I rob the next year, it will be a mix of spring and fall honey, resulting in a darker honey crop - which doesnt sell as well. I sell about 500 lbs a year. Gathering your honey can be a job if you dont have an extractor. And you might decide it is not worth the expense with having two hives. There might be a local bee club that has invested in an extractor for rent - or if you know someone who has one, time your robbing with when they do theirs and extract your honey at the same time.
I use all medium supers. I consider the bottom three as the hive bodies and anything above that as honey supers. Using all medium supers means all my woodenware is interchangeable. Mine are ten frame, but as I age, I sometimes wish I would have gone with eight frame.