He's 80 pounds so in the cabin is probably not an option unless I convince people that I'm crazy and he's a service dog. Neither point is probably that far off.

The flights will likely be SEA to BOS in July though during a red-eye. The return will likely be a middle of the day flight BOS to SEA though obviously I'm flexible on the time of day.

I anticipate it being him underneath and me in J. Just worried about his safety.

Thanks for the comments about wolfhounds. They fly most of the Iditarod dogs so I'm sure they know what they're doing.