I've only seen it on the Camaro, not the Impala, but it'd stand to reason. FWIW, I've never seen a car with it nor seen an option price or code for it. Hard to prove a negative (until we find the ever elusive order sheet).
There was a 69 Impala convertible in my neighborhood when I was a kid that had it. I remember because he was showing it off to whomever would listen! This was in the mid 70's so may have been added by the dealer or the owner. Idiotic option because it wouldn't work when you had any buildup of ice or snow in the inner fender.
'64 Parisienne CS "barn find" - last on the road in '86 ... Owner Protection Plan booklet, original paint, original near-mint aqua interior, original aqua GM floor mats, original 283, factory posi, and original rust.
Methyl hydrate - that makes sense. Though that little canister would get you maybe a couple of feet through 4 inches of snow.
Actually, I remember getting stuck in two inches of wet snow in a level parking lot. It'd be enough to get you moving.
I had a '64 Falcon (first car) with a 3 speed standard. That thing would not get out its own way in the snow, even with snow tires. I used to pull the choke part way out to increase idle, put it in first and let the clutch out. It'd spin while I ran around back and pushed. Chased that thing across more than one parking lot.