Difficult FIL - any advice?

Long story warning - sorry 😬😆

My MIL is a wonderful woman, I’ve never known anyone so compassionate and kind she’s like a mom me. My FIL on the other hand is verrrrry hard work, very immature, rude and pretty selfish. I can tell from a mile off it’s not a happy marriage (I think my partner can tell too) but they sort of just live amongst each other rather than “with” each other if that makes sense?

We have an agreement in place where we pay our MIL as she supports with childcare for our daughter. She quit a part time job to do this so we made her pay back up to where she was before even though technically she’s ‘doing’ some more hours but she wouldn’t have any more money off us (so because we save a ton of money on nursery fees we try to make her life as comfortable as we can outside of what we pay her, cooking meals on weekends for them, taking her places as she doesn’t drive etc just anything we can do to show we really appreciate the help we get).

We always had an agreement that if I went on maternity and wanted our MIL to help again with baby number 2 we’d need to continue paying her whilst I was on maternity leave, even if she has our daughter less hours/days a week for that period which is fine, obviously we can’t expect her to have no income for herself, maybe try to find a job only to quit it when we need help her again so we have no problem carrying on with that and agreed to it long before our first child was born.

Problem is, my FIL is insistent the house is going on the market, and they’re moving away (like an hour away) making our arrangement with my MIL impossible. He’s talking crap because he’s been on and on and on about moving for the last 10 years and as soon as it comes to paying the estate agent fees etc to put the house on the market he backs out because he’s too frugal to spend any money (not to mention he’s almost retirement age and would be looking to double his mortgage to move into the kind of house he keeps talking about). He told us all the house is going on the market after Xmas and they’re definitely moving this time (just for some context my FIL is very disinterested in our daughter and his other grandson and now we have another baby coming and my SIL is expecting too he’s no interest in them either. He was always disinterested in my partner and his siblings as kids too, so the prospect of moving is purely for him to brag about having a bigger house - even though it would only ever be him and MIL in it)

My MIL keeps complaining to me and my partner that she doesn’t want to move, she likes being near us, her grandchildren, her friends and has good bus routes from where they live now to get around if she needs to. She kept an evening cleaning job that she enjoys doing (an hour an evening, a few mins from her house) and has friends through that job. So moving away would seriously isolate her as she’d have to stop the agreement with us and give up her evening job.

I said to my OH if your dad is dead set that they’re moving, it doesn’t make sense for us to keep paying your mom if he’s going to put an end to what we have in place. But equally we don’t want to put pressure on or spite his mom when we can tell she’s in a difficult position herself, despite being clearly unhappy she won’t leave him we know this with certainty so we’re just encouraging her to stand firm about how she feels as it should be a 50/50 decision not 100% his choice.

My OH is reluctant to have a conversation with his dad because he knows when it comes to it he just won’t go ahead and do it it’s all talk but it’s stressing me out so much because my logic is if we need to make alternative arrangements for baby 2 we need to think about it now and not at the last minute before Im meant to back to work, so we’re working on a lot of if, buts and maybes..

Sorry this was such a long ranty post but we feel stuck on what to do? If we say we might need to rethink about what we do about baby 2 based on his desire to move his FIL wouldn’t care but MIL would be devastated (and it’s so sad that my FIL doesn’t take her feelings into account) but equally I don’t want to keep hearing his dad go on and on about this magical big house he’s moving them into and how it’s going to be so much better if it’s probably never going to happen anyway, it’s getting really hard to ignore him and bite my tongue. There’s soooo many other things outside of this post that fuels my dislike for him but I don’t think anyone has that long to read 😂 obviously I try and keep myself polite and friendly in his company but it’s getting harder and harder to keep this up now 😩

So yeah.. any advice welcome please.

And constructive criticism too if you guys think it’s needed, are we being unreasonable?