What is your location?  Very few beekeepers close entrances to keep bees warm.
Bee research has shown the value of good ventilation to remove the evil of
dampness.

An UPPER entrance usually cut in the front edge of the inner cover is
invaluable
in releasing warm damp air from bee breath is used by many experienced
beekeepers.

Bees don't need a HEATED house like you and I.  They are genetically
"trained" to
cluster together for warmth, and have been doing this for eons in Siberia,
Alaska, and Northern Canada quite successfully.

What are you trying to accomplish?

George Imirie