It sounds like you have a good plan already
-Make sure you have his reservation booked. I think someone already mentioned that above too.
-Practice with him in his travel bag to help him get used to it; go to the mall, with him, etc...
-Make sure your travel bag has the appropriate dimensions to go under the seat...
-Plenty of exercise that day; take a long walk and big potty break right before you leave for the airport
-Have a blanket, or something in case it is cold on the floor of the plane
-I know you said you do not want to medicate; if you want to give him something to relax, my vet recommended Children's Benadryl which I used for our international flight
-Take a package of baby wipes, just in case of an accident
I'm sure you will have a smooth trip! I was so concerned about how Remy would do and he surprised everyone
