Geez. I did a cross-country move with ONE cat (now we have a duo) and
it wasn't easy. If we did it again, we'd have to drive because the
semi-feral would be very difficult to take through an airline security
gate for carry-on. Personally, I'm leery of the cargo hold.

It is a long drive, of course, but if your friend can find a fellow
driver - and get a list of motels that accept pets in advance - it
isn't un-doable over a 4-5 day period and it will be easier on the
animals to have their human in plain sight, even though their territory
has disappeared :

The care and feeding of ten animals on the road is no small thing
either. I'd really try to enlist an animal-loving friend into the trip
(maybe with paid airfare for the return).....