Just read that link. I love how a post on snow/ice driving degrades to an "Off-road worthy" debate in 3 posts. BTW, wasn't this a post about dead batteries?
If the HHY gets stuck in snow, it has nothing to do with the "little" electric motor. That motor has 96 ft-lbs at "idle" available to the rear alone. Anyone who says that can't turn a rear axle in snow doesn't know what they are talking about. The issue here is Toyota's traction control system cutting power. I've heard the complaint from people I know and read it numerous times and not just related to the Highlander Hybrid even though the drive systems are different. Toyota just seems to want an overly aggressive setting for some reason. Part of the problem is that one can't turn of TC if you like. I am sure that due to the "Intelligent" system, the new-era fix of pulling the TC fuse in case of emergency isn't an option here either.