Surely better for the children to move sooner than later? Then they can settle and stay in the new place. Would you definitely be able to afford a bigger house in your area in a few years?
Is he concerned that moving closer to his work places too much pressure on him to stay in that job? Does he not recognise the reality of your financial situation and imagine that money will fall from the sky at some point because you 'deserve' to live where you do?
My DP is a bit like this but not as bad, in the sense that I have said to him that I don't believe he wants to be happy. He's more 'muddling along ok' than really pessimistic but it has a lot to do with being scared of the unknown and, I think, of trying and failing. I've had to impress upon him that happy experiences and memories are actively made, most don't just happen and that effort is required but repaid. Also that being moody and negative isn't just his way of being, it actively drags other people down and is a choice. Whereas I am aware of the need to 'manage my own happiness' and do things, both in terms of lifestyle and special occasions, to achieve that.
I think that grumpy people can be very self-pitying and inward looking and would be really surprised to realise that many other people, who appear to have an effortlessly easy, happy life, actually have far worse problems but have actively overcome them.
Whether he cares or not about his own happiness he should about the children's and needs to recognise the impact his attitude will have on them, both inhibiting their enjoyment of childhood in an immediate way and influencing the development of their own characters and expectations.
I can only suggest that you write him a letter explaining how his behaviour makes you feel and why the current situation is untenable for you, then give him some options to help deal wth it, such as counselling, family therapy, parenting cuorses, whatever. No doubt he doesn't think he needs any of this but he needs to understand how miserable he's making you and that you are not willing to live this way, so that he needs to support you in making a better life for the family. He can see this as humouring you, so long as he does it.