The only comparable data I have is the HDRI I baked from this environment that I used to illuminate the backhoe model. It rendered with Cycles (since only Cycles supports equirectangular rendering) in about 45 minutes if I remember correctly.
But that’s for one frame only! Rendering an animation sequence with Cycles would take ~45 min per frame where Eevee’s one-time-bake renders in minutes per frame.
