Update: our plane took off about 45 minutes late. We managed to make our connection at SEA with a few minutes to spare. Despite the hike and train ride from Terminal C to N.
We’re now seated in Premium Economy, having given our nice young middle-seat companion his choice of window or aisle - he chose window.
If all goes well, we’ll be landing in Fort Lauderdale in about 5 1/2 hours.