I would have cut them back to about 6 inches high just above a leaf noad earlier than now. There is still plenty of time for them to bush up before they are planted out in the spring.

I would cut them back almost to ground level now to encourage bushier growth

I don't cut mine till the weather's warmer - but mine are outside on a southfacing balcony. I don't like mine to bush out too much - I tend to squeeze them inbetween lots of other stuff, so what I want is the height, not the width.