After all the suggestions, we went for MyMaps, but then saw the ratings.

We settled on MotionX and it's precisely what I was looking for. It may not integrate with Google or Live maps to import our specific destinations, but I'm ok with doing that manually.

I set the circle to emcompass all of our spots, and it downloaded--with full min and max zoom--at 500MB. Not too bad.

As for the connections, we will have voice and text message service the whole time, mainly to check in with family who is watching our 14mo old, and we'll have free wifi at the hotel and elsewhere around the city.

I just needed something that used the GPS chip alone, with downloaded maps (like your standard Garmin, etc), that would allow us to navigate smartly throughout the area without having to carry a paper map.

Of course, all this is preliminary. I'll only know for sure how well it works once we get there and try to use it.

In the end, our hotel balcony looks out onto the Eiffel Tower, so GPS or not, we're happy.