B) Any issues caused by tying the parking side to the start of winter are well understood thanks to all those other communities who've been conducting live experiments for years or decades. I know of no community using such odd/even side rules that changes side with the New Year, as this could require instantaneous city-wide snow berm removal. Mostly, if you follow the lead of the other people who've parked nearby, you'll find you're on the correct side.

C) I visit Somerville often enough that getting it right does matter to me.