Too Many Toddlers Scenario Starts Nov 3

I have a question. Although I'm not interested in any of the scenarios I've seen mentioned so far (and especially not this one), I'm curious to know if scenarios are playable offline at all. I mean, I know you have to have be online to download updates in order to get the scenarios in the first place, but do they require you to remain online while you play them? I doubt that's the case, but as I said... curious. Because if we can play them offline, and if they're counting players who play, how would they know if players are playing them that day?