I have broccoli growing here in central AR all winter long. I bought the plants and put them in the ground, probably before Christmas, maybe before Thanksgiving. Cold has not hurt broccoli or brussels sprouts and we've gotten to 17 F, maybe. They're growing slow, but the broccoli has the flower heads growing on it now, just not big enough to harvest. They are protected by milk jugs, cans or tomato cages with bird block not for the cold, but against the critters.

all 3 are cool season veggies. Here in 7b NC we plant all those in the ground mid January thru mid Feb for a spring crop. We are still getting spinach from our fall crop and had a good crop of brocolli the first week in January. Snap peas are in the ground now as are my annual sweet pears. You should be fine with yours - just cover if you get a hard freeze....

Lynne