I tend to wonder if the issue is because of Lavender Beds - which is my favorite ward.
Lavender Beds is clearly the most heavily detailed ward, which is probably why the holiday decorations are considerably fewer there (but still look good). For example, Lavender has no snowmen for christmas scattered around the ward except for the area down by the water and the two stalls, where as the other two housing zones have them at various places.
I wonder if they'd have to lessen the detail of the ward(s) to allow for more furnishing slots.