I can't help you if you get frosts and snow, but in the very mild winters of the subtropics, I just cut the plant almost to soil level, and forget about it, leaving it where it usually is - on the edge of a patio where it gets light but no direct sun in winter. Sometimes there are still leaves on one or two of the branches. I just cut them down by about half - that gives the plant a kick-start in the following spring.

Just give it enough water to prevent it from drying out completely. The plant won't be drinking while it's hibernating (in dormancy!), but you don't want the potting mix to harden and become water-repellent.

Stephanie, I live in a climate where it sometimes overwinters and sometimes not; just on the borderline of its tolerance to cold.

It's not very hardy but it's not a true tropical either. It's from Uruguay. Try to find a spot that is cool and bright but NOT too hot. Keep it away from heaters.

It turns semiwoody with age but the individual shoots are probably not long-lived. Cut them out individually as they start looking "senescent". They reshoot fairly readily from the base. Take it easy indoors, tho, as it will probably not be as vigorous.

I'm sure it would like plenty of hours of light, but I do not think it is absolutely necessary as it sometimes overwinters HERE where there certainly aren't any 12 hours of daylight in winter! We're lucky to get any as it is frequently overcast here, and days are short in winter. The key is to keep it COOL. When plants are cooler, their chemistry slows down and they tolerate shorter days.

Decrease watering to compensate (otherwise, it will rot). If it is growing in earnest then water regularly, but if barely growing then water more infrequently and let it dry out a bit (not bone-dry, just "dryish") between waterings. Make sure drainage is good and don't let the soil get too sour.