Flying with my cat but he might be too fat/big?
I am moving from Ontario (small city near Toronto) to Montreal and I wanna take my cat with me on a plane just so the trip is shorter than the train and he doesn’t suffer much. Because Via rail is 10 hrs to Montreal from my city and the plane is about~5 hrs (including the trips to the airport/house). The cabin pet carrier dimensions they allow are 41 L × 25.4 W × 21.5 H cm according to the website but the cat carriers available I can buy are either 41 L × 21 W × 24 H cm which holds an 8 lbs cat or 45L x 31W x 32H cm which holds up to 20 lbs cat and my cat is 20.3 lbs! He is not only a bit fat but genuinely a big cat (we’re on a diet but the vet said he is just a big cat with huge paws). I can never check him in because that is dangerous but I’m wondering if anyone has experience with taking a cat on board. How strict are they with these dimensions? I’m also trying to call them but currently cannot get through to anyone. Any advice would be appreciated!