Just keep your batteries in the house
I like the idea of pressing my electric start (110VAC - plug in a cord, start it and unplug the cord) on my gas SBr and away I go. I put in gas prior to there being snow and cold. I buy fresh gas in advance of a weather report predicting snow. I do this when I top off my car prior to a storm. I haven't used my SBr in several years (not enough snow). I assume that the batteries will not degrade too much if not used for several years.
I assume (if its engineered correctly) that the battery compartment in the SBr is insulated, and combined with the heat generated in the battery during use, will mitigate loss of efficiency effects during cold weather. So keeping the batteries in the house and installing them when needed (outside in the cold or in the garage) sounds like a plan.
I have a long driveway and my street is wide so there is a lot (maybe 6 feet) of heavily packed snow deposited by the town's plow. I also clear a path for the old lady who lives next door from the street thru the heavily packed snow, up her driveway, her walkway to her front door (her son doesn't get there until late in the day.)
Not sure if batteries would last long enough to handle all those tasks. A 2.5 gallon can of gas never ran out even in the worst storm of past 25 years I lived in this house.