" As advanced as we are technologically, I wonder how we’d fare through another ice age?" Some of the places you'd think would be safe/warm, wouldn't be. Ice Ages are very, very dry. Starvation would kill most.
I think you're right. The arable land would decrease so drastically the population couldn't be sustained. And things would likely get very nasty as Europeans and North Americans tried to move south.
Give me global warming over global cooling any day.