Imagine a world that looks suspiciously like Earth. Summer turns to autumn, autumn turns to winter, and winter turns to more winter. The winter endures for several years before summer finally comes again, and itself lasts for several years.
Yes, 'Westearthos' has suddenly become a binary star system, and in just the right way such that the only significant change is the extended and erratic length of the seasons (I know, but bear with me here). The winters are no more severe than normal, and while the Northern hemisphere experiences winter, the Southern experiences summer.
The seasons work as in this question - they normally vary between about one and ten years in length, and a long summer is normally followed by a long winter.
There are several related questions already on SE, but I don't think we've yet seen one addressing this precise question:
How would a modern (2017), Western style society cope with a Westeros-like seasonal cycle?
For the sake of specificity, let's say the society in question is the UK and this is a new phenomenon, so life hasn't had any chance to evolve in response, but we've managed to predict the arrival of winter a couple of years in advance and so have some time to prepare (winter is predicted in 2017, and winter arrives in 2019).
Because 'cope' can cover a broad range of things, I'll limit it to how the society will feed and care for it's citizens. Yes, the England cricket team will be playing an awful lot of away games, and sales of Pimms will take a hit,but let's focus on the important issues.