I've name changed for this but I'm a regular user. It's a bit long but really need help deciding what to do for the best.
Long story, short is that my husband has been having an affair for 4 years with the same woman. I found out after about a year and decided to stay and try to move forward (SAHM, young children etc) with promises it was over etc. Of course it wasn't and they have continued affair since then. A combination of massive gas-lighting, manipulation and EA from him coupled with low self esteem on my part and burying my head in the sand.
In the meantime I've managed to resurrect my career (earn about £60k) although not where I would be if I hadn't left in the first place. At least I have a job though. Husband is a high earner and we have a lovely lifestyle - big house, private school etc. BUT of course none of the important things like love, respect, care etc. It's thrown around a lot these days but he definitely has narcissistic tendencies.
It came to a head a couple of months ago and marriage is now dead. Still living together and not separated but going that way for sure.
Now I need to decide what to do in practical terms.
He says we'll sell FMH, buy 2 places near to where we currently are. We'll have flexible custody. Kids can stay in current prep school and move on (assuming they pass entrance exams) to local grammar school. I work 25
mins away (full time with ability to wfh a couple of days a week). The problem is that we've lived here a couple of years but I don't have very close friends here and my mum is about an hour away. I do have some friends but not super close IYSWIM. Husband says he'll be around to have children 50/50 but experience tells me that will be completely on his terms and he'll run his new life to suit him and I'll be expected to dance to his tune. So in theory it sounds great and the children could keep their current school, friends, activities etc. but I'll be stuck relying on him when he'll no doubt let me down / expect me to facilitate his wonderful new relationship and career 
Alternatively I could move 45 mins away, be close to my mum (who would help with children) but DCs would need to move schools and would then need to go to private secondary (rubbish local state schools and no grammars) so I would be relying on ExH to pay fees for much longer. Much more disruption for DCs in the short term but I know my mum would be much more reliable in terms of help than Ex. I'd be further from work just about doable a few days a week. Plus I'd have to start from scratch again myself and try to make friends.
I can't work out which is the better option. Both have pros and cons and tbh I've had such a terrible time in the last few years that I've lost all confidence in my own ability to make good decisions.
BTW house prices are roughly the same in each area and I should be able to afford somewhere quite nice in either place although obviously not what I have now. I will have peace of mind though I suppose.
Thank you