I would never buy a battery powered lawnmower or snowblower.
Unless I had a tiny little amount of work.
But... When you only get an inch(maybe two) of cold powder snow, I love the battery powered leaf blower. Uber quick and easy for blowing a path out to the BGE, or blowing off the windshield.
As far as batteries you can bring most of them inside to warm up before charging and just leave them inside until you need them. They'll run out of power WAY before they lose power to the cold.
I get three to four feet of snow on occasion. Guaranteed at least once every winter. Even my 11 hp snowblower struggles when it’s that deep. The only battery powered snowblower I would ever consider is the one used to start my gas engine.
I have a 40 volt model it works great for dry snow. Wet snow,not so much. The 80 volt models are supposedly much better. Multiple batteries are a must have, unless she lives in a suburban or urban setting.