I, too, love Regency stories. So much room for tension and great HEAs.
Inciting Incident : Hero’s older brother’s sudden death.
Trigger Set Up: Hero’s sudden arranged marriage
The fire that the MC won’t be able to put out: Thawing his bride’s aloofness and getting to know her.
Clear change happening? Yes, he’s estranged from his family and heading home with a bride he’s barely spoken to. Lots of potential emotions can be triggered. What kind of reception will he get? How will his family react to him? Are there any needs hinted at or raised? Any emotional triggers
Suggestions: I love the set up presented; maybe add in more anticipations of how he will be received? Does he harbor anger or resentment?