Comment from Stephen Parkes:
"Santa moves with the times. His APRS is broadcast both to ground stations and satellite and voice is via digital modes routed over the best available network by a computer on his sleigh. Obviously he has an AM VHF radio on board for legal reasons as air traffic."
via Twitter https://twitter.com/steve_parkes/status/1605869260172976128?s=20&t=I07cOVOebDXopNsbhS06AA
Sounds feasible to me :-)