(and yes, I need to diversify my seed sources ๐)
[Image description: a 72 cell seed starting tray filled with a mix of coco choir, vermiculite, and worm casings, next to a line of 12 types of broccoli, cauliflower, and cabbage seed packets, all but one from Baker Creek.]
Depending on the zone you're in yes. I'm in 9b and rarely get freezing temperatures, so I can grow things over winter that might not survive in colder areas. Some brassicas are especially frost tolerant, so it would be worth looking into and seeing what you can grow in your area.