In the schools I taught at they pulled the children in 15min early in the winter when it is too cold. The teachers still supervise with the children in the classrooms. So, while the child may not have some of their friends there the child would never be in any danger due to weather or anything.

As mentioned, the parents will just need to decide if it is something they can get used to. I too agree that those extra 15min outside are worthwhile for any child about to spend so much time in a classroom!