I would be in a real bind. I suppose unflavored would work poorly, but it would be difficult. If I don't switch out flavors every now and then whatever I'm vaping loses it's appeal. I have flavors That I love, and that I can (sometimes) vape for days on end, but eventually they start to taste like drek, and only switching to a different flavor (or three) for awhile can make them palatable again.
Flavors that I keep on hand are: Boba's Bounty from AVE, Gizzard Juice from Quack's, Coo Ca Choo from Vapetrik, and Southern Freeze from Nicquid.