I bought a massive wire top opening cat carrier! Now it is rather large, big enough for an adult male maine coon

I got it so my cat was comfy travelling to and from shows and to also take him into shows too. But I am wondering now, is it too big? They don't stipulate you have to have a certain sized carrier do they? Was hoping to use it at the supreme as I know it will be very easy to get my cat out of the carrier this way.
What do ya think?