Lillylad, how long is a piece of string? GN gatherings occur whenever two or more people feel like getting together for coffee/lunch/gin/chat or any other thing.
Sometimes, there are half a dozen; sometimes only two. There's no set formula, nothing formal and they can take place in cafés, pubs, restaurants or anywhere people gather.
If you fancy getting together with other GNers in the Lincoln area, start a new thread with "Lincoln" in the title. Then suggest a date and a venue for whatever you have in mind, e.g.: Coffee at Pennells on the --th, anyone?
You'll get a response or two although it might be better to wait until after the holidays are over as folk may be away or too busy to read GN at present.
I know there has been interest in the past from people who are busy at work Mon to Fridays so you may like to suggest a weekend meet which would suit some members better.
HTH