Overwintering experiment worked
I'm a tropical plant nut. For the first time they all survived overwintering. I do not have a basement, so I took a spare bedroom and emptied it out. This is how it worked. I potted up the following: Hibiscus, Alemanda, Tibouchina, Oleander, Desert rose, Brugmansia, and many gingers. Used regular old garden dirt.
I put them all in this spare bedroom Halloween weekend. I cut off the heat and pulled down the shades. Every two weeks I gave each a cup of water. I bought a thermometer and it read 50 degrees. If it got warmer, I cracked the windows.
March 1st, I took them all out and put them in my carport. Even with temps in the 50's/ high 30's, they are already coming back.