You might want to repost this on the Adenium forum.

Not likely with no manipulation....BUT, If you are really good at it..a covered porch or patio,and placed where it gets maximum winter sun while kept dryish, it could make it a few winters In ground? NO way.
Or..and few ever do this for some reason..just make a very small winter greenhouse. Wood and plastic,Or old Aquarium upside down slightly lifted to vent and allow fresh air. Home Depot has been selling Adeniums at a price you can play with them..3-4 under a old Aquarium all winter..might just work. Even if in ground.

Adenium obesums are barely barely hardy in zone 10a... though they can sometimes eke through a winter with overhead protection... these are supposedly 10b plants, and in my personal experience that seems right. I have lucked out a few times when I left mine outdoors as temps dropped to 30F, and it survived, but not without damage. 8b is impossible, even with lots of protection outdoors... mine is in an unheated greenhouse in zone 9a, and it looks unhappy (but so temps have not gotten down below 32F).

I've only seen pics of them outdoors in Phoenix,and doing great in Brownsville and deep south Texas. In Arizona,they are marginal,but worth a try.
In California, it only takes too wet with even normal winter temps to rot them. But,if you were dedicated..a small temp greenhouse might work until May returns.

South florida has some adenium also outdoors.

This post was edited by wantonamara on Sun, Dec 22, 13 at 1:10

This plant, grown in a warm climate, can tolerate an amazing amount of water/rainfall. Seen this plant grown excellently outdoors in Thailand where rainfall can be massive... and plants just get fatter and fatter... look great there.

They like the Florida wet summer. I have seen photos of large fat ones there on this forum a couple of years back. She had some rot problems but it was resolved with added chunks into the naturally sandy soil. The plant was a good 7 ' tall.