I don't think it will be an issue to fill in C actually...BKK is a nice stop before heading to singapore or KL. When flying on such long flights, cutting one stop is nearly priceless IMO (especially on the way back home...waiting 2 hours in CPH coming from BKK in the early morning was really nasty) And SQ direct flights to LHR or CDG allowed for only one stop to singapore but it is only really expensive C or Y, no Y+

I am definitely gonna use that route ;-)