I have about half my stash unheated. I really can't see a problem, but will move more indoors before winter. The problem is with the size stashes we have, it really is a fire hazzard. Every throw some used oil on a bonfire? How about that in the attic above the bedroom?
Anyway, on a lighter note. The OP has his own demons to slay, but the rest of us should just use the oil in our stash up by date code. Even if you are anxious to use a different product, use the old stuff first.
I looked at the PZ SUV Blend I have, it was SL but the date code was near 07. I moved that back in the rotation and am using some SL M1 up, it's dated more like 04. That M1 stash will last for 2 years, so that as well as the PZ as well as the PP and SP I have for my car will all end up about 4 years old upon use. If I vary from the plan, the old stuff will go unused too long. (I use oil up all the same brand at a time: all the this, all the that....)