it's so refreshing to hear of folk clubs starting up instead of having to close down! i agree that the best idea is to have you're set folk club venue, but if you have a special guest and are expecting a bigger crowd try out a larger venue. just for checking it out. there's nowt worse than a big room empty when you can have a small room full, from a performer's point of view. good on ya.
(and book the witches of elswick, i've heard they're very good. shamless self promotion)