With its ill-equipped natural gas systems crippled by the cold, Texas’s exports across the Rio Grande froze up and 4.7 million customers in northern Mexico went without electricity — more than in Texas itself, the Washington Post reported. The spot price of gas jumped 30-fold as far west as Southern California. And all the way up by the Canadian border, gas utilities in Minnesota that turned to the daily spot market to meet demand say they had to pay about $800 million more than planned over the course of just five days as the Texas freeze-up pinched off supplies. “The ineptness and disregard for common-sense utility regulation in Texas makes my blood boil and keeps me up at night,” Katie Sieben, chairwoman of the Minnesota Public Utility Commission, said in an interview. “It is maddening and outrageous and completely inexcusable that Texas’s lack of sound utility regulation is having this impact on the rest of the country.” The Texas market is so large — second only to California’s — and its natural gas industry is so predominant that when things go wrong there, the impacts can be felt across the country. Minnesota’s biggest gas companies are putting forward plans to recoup their expenses by adding a surcharge to customers’ bills, which the state utility commission would first have to approve. Normally, such adjustments to account for winter prices go into effect in September, but Minnesota’s biggest gas utility, Houston-based CenterPoint Energy, says the financial pinch is so great it wants to start billing customers next month — and charging them nearly 9 percent interest until the extraordinary costs are paid off.