How to upgrade only one marketplace or close down a marketplace?

Hey guys, currently listed as an individual seller on both the Canada and USA marketplaces. I am looking to upgrade to professional on the Canadian marketplace, but it is not allowing me to switch over only one. They also have a substantial price difference ($29.99 CAD for CA and $39.99 USD for US). I was wondering if anyone knows how to upgrade only one marketplace or if this is not possible how to shut down the USA marketplace.

Any and all advice is very much appreciated, thanks!