I've lived in the city, I've lived in the country, and I've lived in apartments and houses.
An apartment in the country (if there is such a thing) would be the worst place to live in terms of a long term power outage during a cold weather event like an ice storm.
A house in the country isn't much better if you aren't prepared. I went through an ice storm in a house in the country and it was 3 weeks before my heat, electricity, running water, phone, internet, etc. was turned back on. It just took them that long to get around to me.
A house in the city will get back on the grid much more quickly. I went through a vicious ice storm in a house like this and we were down between 48-72 hours.
An apartment in the city, though? Oof. I live in one now, temporarily, and I'm hear to tell you I cringe at the thought of anything going drastically wrong while we're here. In a little over a month I will live in a house in the city and will sleep much better at night.
I suppose the best thing an urban apartment dweller can do is have a good supply of extreme cold weather camping gear (which I do, but not my whole family!) Cold weather sleeping bag, heavy wool blankets, synthetic cold weather clothing, socks, underwear, etc. It is possible to keep quite comfortable in a very cold place but I'll tell you what those bathroom breaks are a real wakeup experience.
A small camp stove with some Esbit tablets and bottled water can be used quite effectively to make hot cocoa, coffee, meals, etc. but you do have to make sure you have abundant supplies of all this stuff. Bottled water will need to be stored in a place that never gets below freezing.