Hey Warp,
I have, on a few occasions, kept a few semps indoors over the winter. Those were cases with small semps that I did not think would likely survive over the winter due to size. They were kept under fluorescent lights, on 24/7 and situated close to the light. To compensate for the heat and resulting dryness, as well as the normally very dry inside conditions in my house, the plants were contained in individual pots. The pots were tightly enclosed in sealed plastic bags to maintain even moisture. The amount of moisture was such that there was little growth, but also little etoliation. 24/7 lighting did not seem to be an issue for me. Plants totally drying out because I forgot or did not have time to water them in dry conditions was an issue, thus the bagging of the pots. I consider this method to be a relatively safe way to house a semp for a long period of time but not a way to encourage growth or propagation.
If you are confident of your ability to provide enough, strong enough light and keep the plants growing over winter and propagation is your goal, then I think the best path is to do surgical division, discussed in other threads here. I don't know your skill level, but I would not recommend division during the winter for indoor or outdoor plants unless the skill level is high.
"Flooding" when talking about semps, is fraught with risks. Watering semps in a highly porous mixture, where the water passes through the container and out, is likely OK, but I think there are risks associated with flooding them whenever water remains in the pots for any duration. However, seems like there are some interesting possibilities there, suggesting some experimentation.
