Both times I’ve been the northern player and both times I have had the cc cards to stop the progressions down, keep in mind (if i recall correctly) one of the bottom 2 towns starts with a minimal amount zombies meaning that the first wave out of it is delayed by a fair few hours - 12 to 24 approx so you need 1 card on the first day and ideally 2 on the second
I may be at a bit of an advantage here as dragonhelm knights are one of my favorite cards, it may be interesting to run it with competent players but ones who don’t specialise in cards like the knight in that slot