We looked into this before COVID for our daughters English Bulldog. It was the only way he could travel to the U.K. but I wasn’t sure if Cunard were still operating as so many services have got withdrawn or cancelled altogether. And we don’t need it anymore so haven’t checked it lately, hence my comment. Could be a great option for the OP if animal welfare is no 1 consideration.

https://toronto.ctvnews.ca/dog-left-...ours-1.5972600

Once your dog is out of your sight, you have absolutely no control of safety. Even if this dog temporarily survived the extended time without water, dehydration may have affected his kidneys and heart.