It seems that an eight frame box is the width of a typical winter cluster, which is why I like them. Six will work, but the hive has to get pretty tall and it's not a wide (as mentioned). If you put the hives up against each other it will help a lot as far as stability. If you put them low to the ground it will also help as they won't catch the wind so much and won't get as far off the ground as far as putting supers on and (worse) taking them off.