I’ve never lived in an urban area that got much snowfall, but I’ve heard that cities have resorted to picking the stuff up with a bucket loader and hauling it off in dump trucks. Your only practical option if the city does nothing is to try spreading the snow out in some way. When the cold snap breaks, the more surface area exposed to the sun the faster it will melt.
Your neighbors are in the same situation that you are. Whatever you decide to do, all of you should do the same thing together. One possible solution is shoveling some of it back out into the street to melt. The city isn’t going to like that, so everyone has to do it together.
A thin dusting of dirt, fireplace ashes, etc will cause the snow to melt faster when the temperature does rise; darker objects absorb heat faster.
Using hot water or heaters of some kind is really a massive waste of fuel and resources.
If the snow keeps accumulating and temperatures don’t rise, the city residents are simply going to have to accept the loss of sidewalk space until the city starts actually removing the snow in dumptrucks rather than pushing it aside.
A reminder to my fellow rural folks: When the county plow blocks the end of your access drive with snow, remember to plow it back out to the right. That way when they make their “second pass” the snow will be pushed away from your drive entrance.