"No US state has trade with Canada as more than 15%" doesn't disprove that "every US state trades more with China than it does with any other state". GDP and interstate or international trade are pretty different concepts.
And while Canada is a bigger trade partner in total than China, I'm willing to bet that China is more evenly distributed between the states as a trade partner.
No. No US state has trade with Canada at more than 15% of state GDP <https://www.reddit.com/r/canada/comments/6vism4/canadaus_tra...>, and Canada is a bigger trade partner for the US than China.