Just a few more points, Justin, in response ot what's been said:

Public transport may work for you, particularly in cities, but it may be more difficult to get home late at night. However, as people have said, folkies are generaly a sociable bunch amd someone would probably be able to give you a lift back to your base if you were stuck.

Cities a desert? You may find that the urban folk scene is a bit different from what you find in smaller towns and villages. I can suggest two reasons for this (you might like to research it further and see if I'm right!). I'm speaking about England only - Scotland may well be different.

First, city pubs are competing for trade and need to attract the wider public. They may be more inclined to book a folk band rather than let an open session take over one of their bars. There has been a tendency for city pubs to knock down walls and become more open-plan (not all of them, thank goodness) and such pubs may not be suitable for a folk session or a club - song clubs tend to prefer closed-off bars or upstairs rooms, which may simply not be available in many city pubs.

Also the age of the local population may affect the type of music played in sessions. Village pub-based sessions tend to attract older (say over-40) players, which may reflect the age balance in the surrounding area. Cities have a higher proportion of young people, ofen including students, who will, on the whole, not favour song-clubs (unless they're "acoustic" clubs with a stage and a PA system) and will often prefer Irish music to the traditional English stuff you get in smaller towns and villages.

I'm generalising very broadly above, and I know other people will now provide loads of examples to prove I'm wrong, but I think what I've said may help you make sense of some of what you find.

Most folkies are only to keen to talk to people about the music and how it fits into their lives. As you suggest, a more informal context such as an open session at a pub may give you more opportunity to chat. If you go to a folk-song club where people pay to go in, both the singers and the audience may be understandably irritated by background chatter.

And yes, a festival would be great if you want to meet a cross-section of the folk world - paid performers, listeners, musicians, singers, dancers, etc, and there would be loads of opportunity to chat to people with some time to spare. Try to take in a festival or two if you possibly can.

Let us know how it goes, we'd love to hear the results of your quest!
Marje