DS2 was born 3 hrs from first contraction.
The paramedics who delivered him on the bathroom floor were amazing. We called, they rocked up 6 mins later, and DS2 arrived 30 secs after that.
We were waiting childcare for DS1, hence not going sooner. So think about childcare for your oldest.
Have you considered a planned home birth? If I was to have another, and was low risk, thats what I'd be pushing for. Tho you mention consultant, so maybe there are other factors which would make this unsuitable.
Whether a home birth is something you'd like or not, consider getting a big stack of towels out so DH doesn't get the new white ones out of the cupboard and thinking about what you'd do if you did end up with a suprise home birth.
The actual labour was fine - I was wandering round, packing last bits of hospital bag, and then suddenly I needed to push, which was when DH called 999 (apparently we should have gone through labour ward, but we a) I would have delivered without medical support and b) DH didn't have the number to hand). DS2 was fine, I was fine. No problems, just a bit of a shock. Everyone was eating cake at 8am after it was all over.