You often find that clubs have other training sessions besides the main weekday training. For instance, I used to belong to Farnham Runners when I lived down South, as well as week night stuff they meet on a Sunday morning for long runs around the countryside, I am sure the same goes for other clubs.
I found joining a running club when I moved to a new area was a great starting point (have done the same since moving to Scotland). Yes, there will always be those that enjoy the pb/league racing aspect, but there will be people building up marathon training, those who just run because they can etc etc. I'd visit a couple of clubs and see what they are about ...In my experience, clubs are rarely made up of people focussed on ultra running, but there are always people up for a slightly more adventurous run or a longer distance.