So! Obviously if the roads are too bad in your area you shouldn't try to make today's get together. The event is still on, however, and the snow should be getting better as the day/evening progresses.
Also, re parking:
"With the ongoing snow, people are going to be moving their cars to the road to make room for the parking lot to be plowed. People will still be pissy if someone parks in their spot even if they are parking on the road and get lazy about moving their car back their spot once it is clear. Worst case scenario, our guests will have a long walk to get to the Common House. If you have a bunch of stuff you need to unload, you can park in the circle to do so, but it has to be temporary."
So do that.