I’m really glad the textbook provides example patterns to follow for writing (which I struggle with). About the Thank-You Letters, I find it interesting that we should start out with a 季節の挨拶.
I remember thinking this was a bit strange when I first heard about it on a JapanesePod101 podcast that formal letters, even in business situations, often use these flowery, poetic introductions mentioning the weather. In the episode, they said that students have to memorize standard seasonal greetings for letters and email. Like they said in the episode, it’s kind of like writing: “Though the formidable grasp of winter’s coldness has fully taken hold of us, we hope that this letter finds you well…Anyway, your account is now 3 months overdue and has been referred to a collections agency…” Though I guess that softens the tone somewhat.