The EU is putting some pressure on countries to create and submit updated and more detailed geodata to the EU statistical office. Maybe that is an opportunity for collaboration?
Regular mapping is for OSM to handle, and in many cases commercialised (Sweden and UK for instance), but address data is often already in some archaic governmental system and they have problems themselves making use of the data. And no money or knowledge of what to buy to replace it with. So they'll likely sooner or later buy ArcGIS and get locked in.
But EU-countries that are saving money (...) could be made interested in an open source / free software solution, especially if it means they get help and support to get started with a well-documented process, at least if that process has an "EU stamp of approval" so they know they won't get in trouble for some mistakes later. ("Nobody ever got fired for buying IBM/Microsoft/..."). And in this kind of project, it might be possible to even get funding to get local OpenAddress supporters activated. If this is doable, I'd be happy to help recruiting students.