I have heard from another provider that had the turtle bus, that its ok in a bit of snow but in wet sticky or a lot of snow the wheels pick up the snow and it gets stuck in the break.
I walk back and forth to school, although the school is only about 10min walk 1 way for me, it takes us 45mins to an hr to do the school run (due to some of the kids that walk). So I hear ya, on thoes miserable, cold, "I want to quit" days! I only have 1 child that needs a stroller, so i have a jogger with a weather sheild. However, I used to have 3 younger kids, and i had a Runabout Stroller, big wheels, great in the snow (no problem with the break like the turtle bus) light weight and easy to push. I had a triple but they come as big as 6. You can get a canopy and a winter weather sheild as well. These strollers too are a pretty penny, however, as someone else had pointed out, less than a new vehicle! If I find myself with more than 2 little ones that would require a stroller in the future I would for sure get another one of these!!!