I wonder if they are using just one battery. I have an EGO snowblower single stage. I use 2 batteries to do my average sized suburban driveway. If they are only using one battery it's not going to get the job done on one charge, especially in this snow. That's why the single stage snowblowers have 2 battery bays. I'm guessing 2 stage may have even more battery bays.
I use to try and do it with one battery and could get most the way done with a light snow. Heavy snow not even close, and I would get issues with the battery overheating.