RE: Heated washers
I think it is, for the simple reason that regular screen wash will already contain some ethanol. For thermodynamic reasons, having a mixture of different liquids will drop the melting point. Think of 'cooling mixtures'. So adding ethanol will simply increase the fraction of ethanol already in the wash fluid. Add methanol (which, yes, has a significantly greater effect of lowering the freezing point at small % volumes than ethanol) and you get that added effect. I have found that, literally, just a few 10's ml of methanol is enough to turn a frozen washer bottle into free flowing viable washer fluid. It is really very little that is needed. You really want small %ages anyway, as the flash point is lowered significantly in higher concentrations with water.[hr]
One other observation of merit with EVs in the cold:-
Using ICE cars in cold weather I always found/find the window fogged up on the outside for the first few 100 yards, requiring a nudge on the wipers to clear them a few times before it stopped happening. I always presumed this was, perhaps, the air content being at dew point so as you drive through it so condensation appeared on the cold window.
Post-EV ownership, I now know better!
This never happened with the Fluence and I deduce the reason is that that condensate on the outside of the window in an ICE is actually condensate being evaporated quickly off the exhaust system under the bonnet, and releasing warm humid air over the cold windscreen in the first flush of heating of that exhaust manifold.
It never occurred to me before, but was instantly obvious when I realised it did not happen with an EV.