I have outlined most of my childcare arrangements upthread. We have (on the face of it) a standard EOW, and half the school holidays arrangement. Plus one overnight in the week. However, he doesn’t do half the school holidays (dc are at independent school, so long holidays). He (mostly) does: a week at Christmas (may be 5 or 6 days, instead of a week), a week at Easter (may be 5 or 6 days instead of a week), and up to 3 weeks in the summer (usually falls short by a couple of days, plus I end up with extra dc for a few days if they can’t cope with being at their dad’s), then every other half term (again, he only does one week in the October half term, I get the extra one).
eldest dc (severe ASD, plus learning difficulties) goes about 90% of that time. Won’t stay more than 3 days in a row, usually, so eg if a week at dad’s is planned, then dc will come home for one or two nights, sometimes a day too.
middle dc doesn’t go at all, unless it’s a birthday or Christmas Day/Easter day. Then only goes as recognises it’s nice for siblings to have those days with her, not to see her dad.
youngest goes about 90% of the time (not always the same 90% as eldest 😂). Tends to be ok muddling through a week, but every so often it builds up to total refusal to go, usually for a couple of months.
I don’t work, due to dcs’ disabilities, and so I can be more flexible, but I haven’t, since we separated, ever had a whole week to myself, and since dc2 stopped going, not even a weekend to myself, which does get difficult. It also means that exH tends to see me as the default parent, and makes his plans then tells me what is happening. Sometimes it is for work, which is more understandable, but other times it’s for him to eg have a holiday, and I do push back then - he doesn’t get to dictate my time.
it is difficult doing it all myself, most of the time, but my dc didn’t ask to be in this situation, and they all openly state which parent they can depend on - exH complains occasionally that he feels pushed out, but it is him removing himself from their lives, and not being someone they can rely on that causes this. Last year, it came to light that he didn’t even know what school year each dc was in; this year, despite knowing now, he has plans to go away during dc2’s gcse exams - thus underlining how much she can’t rely on him, in her mind. It is, ultimately, his loss.
re: families spending time with the dc, if you put arrangements in place like EOW, even when you are still living together, then he can make those arrangements for his family, in his time. I understand it’s not so easy for you, because your family is further away, but it then become unreasonable of him to scupper your plans, if the dc have already seen his family.
it is always difficult when dealing with an unreasonable person, but try not to fall into the trap,of being stubborn for the sake of it (not saying you are), or sticking to ‘your’ plans because he is being an arse - make sure it’s not at the expense of what the dc want or need. He may not be a shining example of a parent, but he is their parent, and they do deserve the right to equal time with him, if they want. Separated families mean less time to organise things like visits to family, as time is shared. Make sure the dc are the front and centre of plans.