splitting cabbage

I've grown minicole autumn cabbages for a couple of years now, and they are supposed to stand for months without splitting, but mine have started splitting this week

Don't know if it's because of the warm autumn weather...........but it's so annoying.

Any recommendations for a cabbage for eating from now to Christmas that doesn't split and isn't too huge 

I am not sure what you mean by splitting I dont seem to have much luck with caulis or cabbage mine seem to have mutated and have two hearts each of which are loose and not "hearty" at all is this what you mean ?  I can grow Brussels but thats about it as far as any brassicas go!!   

try tundra f1, they are very hardy and ive not known mine to split as yet.