It's 45 minutes each way after a 12 hour shift. That's probably going to work out at closer to 14 hours a day away from the house.
Two young children (under 5)
It's 45 minutes away from the support network for the family, so no more ability to have the grandparents/uncles etc to easily pick the older kid up from school if there is a doctors appointment, no easy ability to have baby sitters etc*.
It's an entirely new school for the older child who already has issues and has just started settling into his current school (the new place is small enough it looks like they only have one small middle school, same for primary and no upper).
It's an entirely new GP's practice for his partner who has spent several years starting to find out what some medical issues she has are, and potential treatments (I can't actually see any GP's within several miles of where they'll be).
45 minutes isn't a terrible commute if it's something you've chosen and taken into account when you've looked for your job.
When the move also removes you from every element of support you've got, and at the same time massively increases the load on your partner that's an issue.
As I think I said, it's also going to require them to get a second car as the local services are pretty poor, and with 2 under fives getting on the few busses is going to problematic.
He's grateful for the chance, but at the same time it's going to be a very difficult change for them to make and it's going to make their lives more difficult in many regards, but it's the only option they've got and he's probably going to have to look for a new job if they do move as he'll probably need to be at home more to assist in childcare.
In short, yeah 45 minute commutes aren't too uncommon, but it's definitely not something you can just shrug off. He specifically quit his old job a few years back to get one closer to home when the first little one was on the way (and lucked out into a job that was actually better paid and has good bosses, most of the work around here is minimum wage).
*At the moment they live within 10-15 minutes walk of myself, my sister (his mum), his father and another uncle so if there is any problem they've litteraly got help minutes away