Well this was a learing experience 😅. Very glad I'm taing part in this as making a binned hex map was on my list of things I have wanted to learn how to make in d3, and now I can cross that off. I used a great example by Lars on Observable using hisd3.hexbin plugin. Could do with some tinkering, but it's time to move onto the next day as I am behind.
As ever code can be found here