If some can get established camellias to move (I've never had any success with this) then the much more dense and fibrous roots of box surely make this possible. Probably quite large specimens of this old favorite have been moved many times. You will have to be able to trench around them, lift and transport to new location--before new spring growth (shoots) appear.

i never had problems to transplant boxwood , even 20 year old plants.
even when they only have a few roots , they will re-grow very easy.
when they don't have enough roots , i plant them in a protected site , in shade , for 1 year.
1 of my neighbours transplanted a 100 year old boxwood , succesfully.
make sure that you give it enough humus, water when it's dry in summer.
boxwoods grow best in full sun , for several reasons .
(habit and diseases).
the dwarf forms and some of the species are better in partial to full shade.
B-boy : the boxwood encyclopedia is the best book of what you can find for the genus buxus.
the autor is writing a new book only about the boxwood species.he's the curator of the collection in west virginia .

Thank you for the info!

Here common box (Buxus sempervirens) has better habit and foliage color with some shade. Asiatic boxes like hotter conditions, probably like it best on south facing walls.