while you say unlikely, don't forget, just a few years ago, many would have said it was unlikely we would have seen TCX on JFK/MIA/LAX/BOS.
Just to clarify, I was only suggesting the ski routes might be unlikely, or at least less likely than say the Caribbean or places like Thailand to the East. Capetown did cross my mind but I don't know whether demand would be sufficient, whereas those destinations in the US that TCX now operate or plan to start next summer were certainly all routes unserved or under-served (JFK) according to MAN a year or so ago.
Interesting thought about Norwegian Skip, but don't you think the signs are they are setting out their stall for BHX?