[Perfectlap]

I'll just add one more point because I see this done so often when people discuss non-winter tire performance on snow and ice. People here often say "they're doing well". Or one forum member even posted that he was able to hold a straight line on summer rubber in snow on his drive home as if that was some sort of accomplishment.
This sort of feedback isn't really saying much at all about the merits of non-winter tires in wintery conditions. A tire proves itself in conditions that require it to punch above its weight when things don't go to plan and they need to take evasive action or stop suddenly. For instance, when some dimwit on all season-tires misses a corner and ends up in the oncoming lane straight at you. Or when the car in front of you locks up and you have to dart quickly to left or right, or perhaps you're boxed in and have no choice but slam into the wide pedal. That's when a non-winter tire proves itself. You are only as safe as the upper limit of your tire. Believing that a tire is performing well when you are NOT really testing its limits in any way is simply overstating the effectiveness of the tire.
I'm glad to hear you guys have back up vehicles, but those of us who dont' have one should not be driving a RWD car on all season tires in any kind of snow that is accumulating beyond an inch or in temps well below freezing. This simply is not safe for you or the other motorists. Leave the car at home or switch over to winters in the early part of the month you typically see snow. It's simple logic, the better an all season tire performs in winter the worse its going to do in the summer. The better it performs in summer, the worse its going to perform at the exact momment you need it to pull you out of danger.