I'm very happy to say that it turned out nicely, and the husband even went back for seconds! I made a double-batch so we could enjoy leftovers. The soup turned out a little watery, so Matt helped me thicken it up with a bit of flour and some cold water. We garnished the soup with crackers, green onions, and cheese, and paired the dish with a light salad. Honestly, the texture was very similar to Rapunzel's Squash-Hazelnut Soup we made for my birthday party in April, but this recipe was much easier.
Here's the recipe from Francis if you want to try it yourself! I think kabocha would be available at Asian grocery stores in America as well. Happy cooking! :)