Wow, you must be hyper sensitive to smoke smell. We are not smokers and do not like smelling it, but we have been on 14 cruises now and every one of them allows smoking in the cabins. We have NEVER wakled into a cabin to find it smelling like an ashtray nor have we even smelled a smokey cabin smell. The stewards do a fantastic job of cleaning the cabins between guests.
I would think that on a line like Seabourn you would have even less of an issue.
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise
NCL Dream October 2006, RCCL Mariner OTS June 2007