I have only tried to overwinter one large coleus in the house. It was in a 14" pot and got very leggy and bad looking by late winter, so I ended up taking cuttings from it to root for new spring plants. Since then, I just take cutting and pot them up this time of the year. I know there is a green house here in town that keeps large coleus going for years inside in pots, but they have much better conditions then most homes do.
