Yes, Sweden is to big for that. Train from one end to the other takes well over 12 hours, so getting back again in the same day is hard enough, and getting to play anything in between is impossible. However, a vast majority of the population lives in the southernmost third of the nation, so the problem isn't that big in reality, but there is still no chance someone is spending 2 hours and €20 each way (what it would take me to get to Stockholm by train) is nothing you do just to play one game of Civ.
Thus we Swedes tend to get together to play only at the big conventions (of which I only regularly visit two each year). There are local groups of people playing more often, but from what I've heard, those groups usually are just four or five people, barely enough for AdvCiv, and certainly not enough for CivProject.
In fact, I'm in the process of starting such a group with my friends here in Linköping as basis. It only took me 3 years of trying to get 4 willing people in the same room at the same time.
So far we have played one game (AdvCiv, as we wasn't 5 players, the minimum for CivProject), and it was a success, but so far I haven't managed to get four people to be able to play at the same date again. I'll continue to try (if you live in Östergötland and want to join, please tell me!!!)
I've thought of setting up a forum, mailing list, or similar, for Swedish Civ-players, announcing it at conventions. Never got "tummen ur arslet" and actually do it though. Hopefully I'll get going before GothCon this Easter...