So I decided when I got my Grom that it would be my only form of transportation, more or less for fun not necessity. I've enjoyed every second of it.
Here is a short video of me riding in the snow. It's a super crappy and boring video, but it's just so you can see what the Grom did. The first part is on my way to work and the second is on my way home.
I'm running completely stock, including the tires. The Grom did surprisingly well, only having a few spin outs and slip ups which were probably my fault anyway. Since the bike is so light if I ever started to fish tail or anything I could easily save myself by using my feet. As far as riding a motorcycle in the snow, the Grom has got to be one of the best to use.
I know this isn't much snow compared to what some are experiencing, but for myself and Portland it is. I'm happy to say that the Grom performed well and it's more than possible to drive it in snow, just be careful.
Also I'm pretty sure my fingers got frostbite since it was 19 degrees F outside (-7 C)