What nationalities I headcannon the characters in ItW
I've imagined in my head that the story takes place in vague Germany due to the tales being based on the Grimm's
So the Royal Family is German for starters
The Baker(and Rapunzel by default) I like to imagine their father is Danish- with the hc that the Narrator and Mysterious Man are one in the same, mostly a reference for Hans Christian Andersen- though of course the Baker doesn't even know that he's half Danish. Mother is German. Rapunzel doesn't know crap about her nationality
Baker's Wife is a hardheaded German. I don't know what else to say
Jack and his parents are British and moved to Germany before he was born for the sake of his father's job and whatnot. Jack has a British accent and knows broken German
Cinderella, I imagine is fully German, though her step family are French, so she learnt French as well. Though they all speak German and English just fine
The Witch is German. Little Red is German. Ok moving on.
Whether they're speaking German or English throughout the musical, I like to think it's English. But this is all my interpretation in the end