I couldn’t justify dragging a dozen or so birds 800 miles to just kill them.
Gotta be decent bird hunting within 800 miles? Or at least a preserve.
To answer your question about transporting the birds. I’ve only ever driven maybe 100-120 miles with birds(chukars and pigeons) for training. The temps were a bit warmer as well. I’d think they’re be fine if they had access to water and the cages covered with a tarp or canvas.