In the ho, ho hold. 😀

How much antler room do they need?

Boeing 747 freighter main deck is the highest available pressurized main deck (Beluga is unpressurized, so are Ruslan and Mriya, the only fully pressurized outsized cargo deck higher than that of B747 is that of the Galaxy, which is not commercially available). Both elephants and giraffes have travelled on B747 freighters. The trouble is, B747 freighter is said to be flown by cables exposed in the ceiling of the main deck… so both giraffes and elephants have operated B747!

Reindeer probably are not tall enough to operate B747…