Wayfinder does not require data connection. Maps and all the other required data is stored on your tablet.

I was in Rome last week and used my Maps briefly in the city and most of the POIs near my hotel were in the Maps. Wayfinder uses TeleAtlas maps and the updated maps are version 2008/01. I would think that they are fairly well up to date.

If you use A-GPS feature, it will download satellite information over packet data, but that is easy to disable in A-GPS settings.