There are people on the forum from Oxfordshire (BigRedDog springs to mind) and I've both met up with quite a few and gone on lots of meet-up's, trips and holidays.
Re WT4's post, I would definitely go to the half-term camp if I were you - you will never look back. It is so near to us and they have a great climbing centre there that we go to regularly.
Most of the people who go on SWK trips are not on the forum but you will usually meet a handful that are and esp on camping trips, quite a few are.
We probably can't make that camp as my daughter is down to spend time with her dad then but I swear to you, people will be friendly and welcoming - you just need to feel the fear and do it anyway...
Regarding a local meet-up, I am always happy to meet up (private msg me if you are a member) but I suggest that you pick a date, time & venue and just post it up on the forum.
When I first came on to the forum, what really made friendships for us very quickly was going on a short SWK trip.