>> row covers, and hopefully a cold frame
If you have any interest at all in "leaf broccoli" , try the Italian "Broccolo Spigariello" (Brassica oleracea var. 'Spigariello'). It's a strongly-flavored green, but a good brocoli-flavor. For me at least, this is one I don't eat raw, becuase it is so strongly-flavored. But steaming or a brief boil makes it nice.
It may take 45-65 days to reach full size, but it's hardy down to 25F and edible even when small. Mine overwintered fine despite freezes and being snowed on, so it's a good plant to practice row covers on. .
