I think you need to make a cold hard facts list of who is putting what effort into this relationship.
You:
-
all the travelling. All of it.
- the disruption of being away at the weekend
- disrupting another person (your daughter)
- putting up with being a farm widow
- prepared to move for him
- prepared to take your daughter away from her friends and change her school for him
- prepared to change your job for him
Him:
- well, the square root of fuck all by the looks of it
He might be prepared to change house which is a big thing. But - you haven't asked him to, and actually I'm seeing much beyond hot air on the moving.
I actually have some sympathy if he's settled and doesn't want to move.
But this "space" nonsense is stalling bollocks.
He has a 3 bedroom house. That means there's a spare room that can be a "man cave". But surely if he needs space, he'll get that the 5 weeknights and 1.5 weekend days he spends on the farm, no? 
Even if you both decided a bigger house was needed, you'd be crazy to buy it before living together. He should create his "space" another way for 6-12 months (that spare room, the farm, etc) whilst you check that living together works.
Honestly, I would cut your losses. I know you love him. He may love you. But when you dropped the midweek drive over (yep, you doing it) his response should have been "I'll come to you that night, I'll stop the farm work". It's not his farm and he has a full time job. If he can't prioritise his relationship for one night a week by telling his family NO (or paying for a farmhand to cover him) then that relationship simply isn't that important to him.
I wouldn't be prepared to change my child's life, for someone who has already chosen the farm over you. I wouldn't change my life either, but at least that's yours to take risks with.
Are you really going to move your child an hour from her friends, grandparents and school for a man who can't even make one compromise for you?
You'll be back on here a year later if you do, frustrated because you never see your boyfriend. Right now, you probably don't feel lonely or that he isn't interested because you don't see him. He's already not even there some of your visit time! How are you going to feel at 22:00 on yet another night, on your own?