None of ours are in, none are rugged. They've got field shelters, trees and food. It is wet and cool but even the part Arab stays out unrugged in much worse. The natives don't even notice this.
Got fed up with my grey horse refusing to go out into his field today (he's planted himself in the yard with access to the shelters/stable since Wednesday evening!) so threw on his WINTER full neck rug and the other WINTER one onto other woosy horse and lobbed them out! They weren't impressed - wooses.