EUROPE REMEMBERS WHAT A BAD WINTER CAN MEAN: A late-winter cold snap in 2018 sent energy prices skyrocketing. Britain warned that some industrial uses of electricity powered by natural gas could face shutoffs. It didn’t come to that, but no one wants to see that scenario. Nor a repeat of the disruption from January 2009, when a pricing dispute between Gazprom and Ukraine led to a two-week shutoff in southeast Europe. It cut off gas heat to 70,000 apartments in Sarajevo, the capital of Bosnia-Herzegovina, forcing people to stay with relatives and emptying stores of space heaters.