Andy,
I know it's not a lot of help to you know but for as long as I can remember the west mids winter series has been run 2nd & 4th weekend of the winter months @ Kiddy and Cov' respectively ..... might be worth planning around those next time ..... although no doubt there are other series local to you but in the other direction that run 1st & 3rd
It would be such a shame if you didn't hold your indoor meetings as I think that your venue is the best option we have in the southern counties.