Most beekeepers in the PNW use 2 deeps as the brood chamber, honey supers are beyond that point. Even then some prolific queens can use as much as 3 deeps as brood chambers. More bees means more foragers which means more honey is harvested as long as good pastures are present.
As to your problem with only 6 frames built out, I assume you're talking 10 frame equipment, consider these factors.
Bees will build comb under their feet, if there isn't enough bees to move to a new frame they won't begin building comb on it until there is.
Bees prefer to build up or down verses sideways, this is one reason bees do so well in 8 frame equipment.
The outside frames (1 & 10 in a 10 frame hive) are almost always storage frames (honey and pollen only).
If you have 6 frames drawn in 1 super (probably 3-8) then pull the super just to the outside of the drawn frames and place it between the outside drawn frame and the other drawn frames: If your hive looks like this, E E D D D D D D E E, where the E= empty frames and D=drawn comb the make it look this way, E D E D D D D E D E. The bees will then move off the storage frames, since their presence isn't needed their like brood requires, and draw comb on the frames placed between the drawn frames. Once those frames are drawn to the same with the remaining empty frames.