I agree that food is going to be the biggest problem, right after an awful lot of people freeze to death in the northern tier of states in the U.S. If we are truly going into even a little ice age, I'm expecting the climate here in north central Arkansas to be close to what I grew up with in the Minneapolis area, except for possible mid-summer frosts that will wipe out a whole season's crops. We grew nice gardens in Minnesota back then...I'm talking late forties and into the fifties. It was cold then, up until the late fifties.
I'm prepared to garden like I remember it being done in Minnesota when I was a kid. If we get a severe solar minimum, most of those up north who don't freeze will starve after the first crop failure if not sooner.