Hi  everyone.
     Like every thing else, empirical thinking tends to get involved, and all kinds
of thoughts emerge with great potential.  Regarding bee size and climate, work
experience in different climatic conditions may throw some light on this subject.
I have worked with both large size and small size bees in tropical and temperate
climates, as I am sure many others have.  In both environments, I have observed
equal diligence and work behavior of honey bees.  To me, honey bees have developed
special "abilities" to cope with their sorroundings during millions (?) of years of
existence, (among which cell size may be one of them) Thanks to that, they have
survived, regardless of climate and predation. While I write this, I am recalling a
paper that I read quite a few years ago about how honey bees utilized the
excrements held in their intestines for warmth in temperate climates.  I wish that
I could recall the author to cite, but I am sure it is there in the archives
somewhere.  One of the many wonders of honey bees!I think that there is much to be
learned yet about our honey bees and that we should tread carefully onto their
abode.
Best regards.
Dr. Rodriguez