Hi there Mark,
There are at least another 3 from HERAS going for the weekend and possibly some members from East Riding Astronomers. Sometimes some of the members go just for the day and the evening then return home. It is a really well organised weekend.
The only drawback I guess is not being able to have a proper shower and of course the toilets which are drab, but apart from that it's not too bad. I have been to worst places - like some of the music festivals.........and they are bad!
There are quite a few things going on during the day, although many people do their own things and don't always go to everything. Last year we hired mountain bikes and went on some of the new cycle tracks - they were great. We also went to Whitby for a while during the afternoon to pass the time when things were quiet. Like you say, the main time for the proper observing is the night time. The daytime is a great time to talk to various members of the other societies and see what equipment they have and gain further information.
That's about as bad as it gets, so nothing to worry about.