Around 2007, 2008, I planted an Oleander here just to see what would happen. I mulched it up really well and provided a windbreak, but nothing beyond that. It limped through a couple of winters and died. Part of the problem was I had sited it in a mostly shady spot under these huge Willow Oaks. It got maybe an hour and a half of direct sun in summer. And Oleanders are sun hogs. Had it been a full-sun spot, it may have been able to heal its winter damage every year. Instead, the damage simply accumulated and accumulated until it reached plant mortality level.
Oleanders are really hard to grow here. There are some "hardy" types, but I think they may only be a degree or two hardier than the rest. Dwarf varieties might bed easier to protect and mulch up. The drawback is protection schemes are unsightly.