I take cuttings, root them, pot them up, and then give them a pinch to promote branching.
They take up less space this way, although I've had some of the cuttings get fairly large by early spring.
In that case, I just do it again and have even more.
They do have a tendancy to try to bloom -- is that a light-regulated function in this plant?

Nyaa - there are two different types of coleus available. you may have the type that was started from seed and is more prolific in flowering, but even the coleus propagated from cuttings may start flowering now. If it's a seed coleus, you might just buy new seed next year and not have to hassle w/ overwintering the plants. If it's one of the cutting propagated coleus (which are usually much more expensive), then you'll decide if it's worth your time & trouble to keep the plants over the winter. The newer coleus were not available to our mothers - coleus was much more exotic back then than it is now, and not so easy to find at the nurseries in 4 packs in the spring.
I've added a link to a Bachman's 'tip sheet'. Bachman's is a long-time nursery in the twin cities area. Their tip sheets are quite nice.

Here is a link that might be useful: Bachman's garden center, twin cities, Mn

I have a cutting propagated coleus that is expensive to buy so I put one of my potted plants in a south window and in the spring I take cuttings and have all I want. They root so easy in water.