There is a nursery like this on on the the islands on the west coast of Scotland, which works really well.
We are looking at having one here, and we are very, very exposed! At the moment our island kids travel to a neighbouring island for nursery. The way I see it, when they get 'storm-stayed' at home, they are still outside playing or 'working' on the farm anyway. My kids only stay in if there is a danger of something blowing into them, lke the bins or bits of fence/rooftiles...they regularly blow over themselves in the winter
That would be for 2.5hrs a day though. And I have to admit, I'd be delighted knowing they'd had their 'outdoor' time and I wouldn't have to take them out beyond the garden!