I live in the Marais, too, but it's an easy transfer to the #1 Metro, which will take you directly to Porte Maillot. And as for the Americans in the non-smoking section, I can deal with that, if I get in 15 minutes earlier and it's cold and rainy outside and I'm not under the awning or next to the outdoor heater. I think the RER A stops there, too, although I've never gone that way.