Complex sentence: It marked the first time that a Super Bowl was held at a cold-weather city--the domed stadium saved the crowd at the game from the very cold and snowy weather, but the weather did affect traffic and other logistical issues related to the game.
Split into simpler sentences: It marked the first time that a Super Bowl was held at a cold-weather city. The domed stadium saved the crowd at the game from the very cold and snowy weather, but the weather did affect traffic and other logistical issues related to the game.