When we first moved here our eldest 2 dc went to a school which was 18 miles away, by school bus. There were endless problems with the other kids on the bus (this was a very (imo) expensive private school (paid for by dh work) btw.
Evenings, weekends & holidays were miserable and depressing - they didn't know any local kids, the holidays often didn't coincide and because of the journey time they were home too late to join in the local after school activities. It was quite intense on the family as they were so mutually dependant yet at the same time so sick of each other.
We then decided to stay long term, so pulled the kids out of the far away $$$ school and sent them to the local schools. Right from the word go it has been fantastic. They made friends with kids living locally, have a social life, and are a lot less stressed being able to walk a few minutes to the local school.
Even dd who went to nursery in the next village, only a couple of miles away is now at a Kindergarten in our village, so they all walk to their various places and even being a couple of minutes as aopposed to a couple of miles has made a huge difference.
For me, based on our experience, I would not consider to send them so far away unless there was absolutely no alternative.