Several recent widespread temperature extremes across the United States have been associated with power outages, disrupting access to electricity at times that are critical for the health and well-being of communities. Building resilience into the energy infrastructure to such extremes needs a comprehensive understanding of their spatial and temporal characteristics. In this study, we systematically quantify the frequency, extent, duration and intensity of widespread temperature extremes and their associated energy demand in the six North American Electric Reliability Corporation (NERC) regions using ERA5 reanalysis data. We show that every region has experienced hot or cold extremes that affected nearly their entire extent, imposing simultaneous stresses on the system, and such events are associated with substantially higher energy demand. The western U.S. experienced significant increases in the frequency (123%), extent (32%), duration (55%) and intensity (29%) for hot extremes and Texas experienced significant increases in the frequency (132%) of hot extremes. The frequency of cold extremes is decreasing across most regions without substantial changes in other characteristics. Using power outage data, we show that recent widespread extremes in nearly every region have coincided with power outages, and such outages account for between 12-52% of all weather-related outages in the past decade depending on the region. Importantly, we find that solar potential is significantly higher during widespread hot extremes in all six regions and during widespread cold extremes in five of the six regions. Further, wind potential is significantly higher during widespread hot or cold extremes in at least three regions. Our findings indicate that increased solar and wind capacity could be leveraged to meet the higher energy demand during such widespread extremes, improving the resilience and reliability of our energy systems in addition to limiting carbon emissions.