Hi , I think you will enjoy the move as long as you don't think every day is a holiday.
We have had a place there for 13 years on Novamar opp the school . We do mostly winters and a few summer weeks but retain a bolthole back in the UK.
The school will be fine for your children as we know Icelandic / Chinese / english and french people who have there children there .
The problem may be getting in as far as i know its full, but there maybe better news on the horizon as they have just approved an extension for the start of term August ,though it may be temporary cabins until a larger permanent school up the hill is built. This is Spain so anything could happen.
Winter times are far more comfortable though you will find a lot of restaurants may close for part of it, they deserve it .
Good Luck