>But absolutely, completely, totally, 150% useless in snow, apparently!

Odd. I have one as my fleet car. Seemed to do very well over the last couple of winters with snow tyres on.

You can't just boot it and expect the Traction Control to sort things out though as you can with some vehicles. The Prius T/C system is very agricultural, as all it does it chuck the breakers on the Inverter assembly, cutting the electric drive. The reason is that if a wheel spins and then grips, the torque from the 'leccy motor is quite capable of snapping a driveshaft. Driving with the "lead welly" on a slippery surface causes vigorous "kangarooing".

If you take it with the standard issue tyres, snows are a "must have". The types fitted as standard on delivery are all low rolling-resistance for economy and are indeed utterly useless in snow and/or cold weather. If I were buying one and not planning to fit snows in winter, I'd be insisting that something more suitable for all year round use were fitted.