Are they going to pin it and then put him in plaster or traction? If traction then you'll be in for a while. Maybe 2 weeks, they'll have play specialists on the ward who will help you explain the operation to him. Don't lie and say it won't hurt because it already hurts, just say it will hurt when you wake up but it will get better. It's always so much worse when parents tell children it won't hurt because it does.
Plaster wise you might have him in a hip spika type thing or if not it will be toe to hip.
So sorry you're going through this and not even near home! Would it work if DH took the kids home and another family member came to baby sit them at your house and he came back? Or can one of your parents come to you and help?
There will be a parents room on the ward, use it. Tea, coffee fridges for your food and some of your child's fave yogurts or puddings whatever after the op. That will help the sore throat from the tube.
Don't be afraid to ask the staff to help, they will be expecting you to do most of the care because unfortunately that's what the wards expect nowadays, but someone can watch him for you to have a shower etc.
If you're not breastfeeding you won't get fed unfortunately because you're not the patient, which is shocking but I've never worked anywhere it's been 'allowed' but if you order toast in the mornings you'll probably get enough for the 2 of you.
First 24 hours after the op you probs won't get any sleep because they need to take very regular observations to make sure he's recovering ok, and they're not quiet but we do try and do them with minimal interference.