I'm absolutely loving your posts, mummy. Certainly sounds like 3 is your 'magic number' and that you've got things sussed for making life easier 
For us re. a house move: we had downstairs extended last summer so things are comfortable now for us as a family of 4 (plus our dear little dog). We cannot extend upstairs, however. We have a 2 bed house; our bedroom is a decent size but the girls room ia snug. We could squeeze a baby in with us for the first 6m but would then absolutely need to move.
That's okay because we know that when dd2 is around 3yo, we would need to move anyway to accommodate the needs of growing children.
We were out today and saw a family with a newborn. Dh said again how he would like another child. He said he wouldn't mind if we didn't; that we have our family and more children would be a bonus. So though I know he would like one more, I don't feel pressure. I just dont want to miss the boat through hesitation led by over thinking.
But then, I don't want to rock the boat, either 
Anyway, I think the fact that we had a hard time conceiving dd2 has skewed things for me. I can't figure out if I really, really do want another dc, or if I've blocked that feeling out.
I put so much into wanting dd2 that I lost myself in it. I'm glad to be 'me' again, if that makes sense? I'm too aware of cycles, fertile times of the month for another pregnancy to just happen. I don't want to be consumed by ttc again.
Then there's the repeat CS/recovery issue, but I know that should only be a short term problem.
I really do like the idea of three daughters, or to have a little boy would be wonderful (I even have a name for my imaginary boy
)