As someone else with an extensive collection, I am going to let you know how I do things. First off I always have one "special" bottle open, but only one. I will usually have about three or four other bottles open of various styles such that I can enjoy whichever particular style I want on any particular evening. When I want to treat myself, or when I want to treat a guest, The special bottle is open.
I find I will finish one of these special bottles in about four to six months so I buy two to three a year.
Now I noticed that you have Bruichladdich Black Art amongst your "specials". My advice: Grab another if you can find it. I reviewed this bottling a few months ago and it is perhaps the finest whisky I have tasted from Bruichladdich. Jim McEwan did a fantastic job blending that one.