How are the leaves? I've let kale overwinter and it gets pretty tall but any new leaves in the spring are too fibrous and tough for my taste. I prefer collards in most cases. I'd be interested in what cultivar you grow.
The leaves are great, as long as you harvest them while they are green. I'm not sure what the cultivar is as I usually let them go to seed, collect the seeds and start over when they get too tall. Brassicas tend to cross pollinate, as far as I understand it. They get super tall, but I usually stop after 5 ft. and start over.