Welcome
First of all I would like to welcome you to Yorkie Talk. If Mickey is going to have a ride under your seat, then all should be well. You will have to purchase a ticket for him -- and I would do that in advance to be absolutely positive that there will not be any surprises when you get to the airport.
If I understand your post correctly and Mickey will be locked in a crate all day in a strange condo -- that doesn't sound like much fun for him. I would avoid taking him to a kennel. Is it possible to have a house/pet sitter stay at your home and take good personal care of Mickey?