African Garden + winter

An Indoor Gardening Mystery Solved
sad plants, except for the Oxalis and the coleus

I love my husband, he's so smart. He figured out why I chronically underwater my houseplants, how I can walk past a wilting plant indoors that, if it were outside, I'd water immediately. It's so simple. He observed that when I go outside, it's usually to garden or to take photos, so I'm thinking about the plants. By contrast, indoors I'm usually busy doing something and, when I notice the poor plants, I think to myself that I'll water them later, when I'm done doing whatever it is I'm doing, such as carrying an overflowing laundry basket. Of course, by the time I finish my task, I've forgotten about the plants and moved on to something else.

The plants have been in the house only since the middle of November, and already there has been a marked decline (compare), except for the Oxalis and the coleus, although the Fuschia has started to rally and has buds. Now that I know the reason for my failing, hopefully I can correct it.
How do you keep your tender plants alive over the winter?