...my local bank only has 8 extra large safety deposit boxes. After being on the waiting list for 7 years, I finally got one. My previous box, a "large" held only 2 PCGS blue boxes with enough room for some loose stuff on the side. This new extra large box is less than double the annual fee, and holds 8 PCGS blue boxes (with the lids on)... Sometimes, it is the little things in life that make you happy... this is one of them!
That is a long wait, probably pretty common in larger metro areas like yours. I have most of the larger boxes in my one institution filled up with all my garbage.