Our experience was that most childminders will only know on short notice if they have places coming up. We were also trying to be early birds to find a childminder half a year ahead of when we need one but most childminders told us they have no idea whether they have spaces in half a years time.
The ones that did have spaces were the ones starting out from new. In the end we found someone through facebook so it's always worth checking out the local FB pages.