Hi Koko, Yes, it is always possible, with a lot of mix/match outfits and just take the basics. Are you flying into port? If not, I would just use two and still pack sensibly. Carnival also have some self service laundry rooms, you can plan on washing during the cruise, then you wouldn't need to take as much...If flying too, remember the weight restrictions, keeping it under 50 pounds is difficult for just one piece of luggage...
Well I always pack 2 in 1. (And my other half is 6'9") if that tells you anything
I couldn't do anymore then that and I pack light because I always end up wearing the same thing anyways. Good luck!!
__________________
CRUISES
Century 4/1998
Mercury 4/2000+4/2006+7/2007
Sensation 4/2002
Infinity 4/2003
Summit 4/2004+4/2005
Carnival Liberty New Year's Eve 2007
Liberty of the Seas 5/2008+11/2009
Solstice 4/2009
Oasis 4/2010
Allure 1/16/ 2011
Equinox 4/11/2011