I moved when I was four days overdue with DS2 and DS1 had just turned 2. It was... stressful!!!
Do: accept as many offers of help as possible from friends and family.
Do small jobs that you can achieve on the yoga ball i.e labelling boxes
Make sure your hospital bag is filled and is the last thing you pack, just in case!
Send your older kid away for the day of the move with a family member or babysitter. The whole day if possible.
Get the kids room set up first when you arrive.
Direct everyone from a chair at the new place, getting them to put the correct stuff in the correct rooms. Do not plonk it all someone "for now". It will not be moved.
Get some oven meals or online shop delivered for the evening of the move. Easy, simple food an snacks. You will thank your former self for this.
Pay someone to clean. Or do little and often and start the week before the move. You don't want to over exert yourself the day of the move with loads of cleaning.
Unpack as much as possible as soon as possible. Do not think 'we will do it after the baby is here' because you won't and it will never happen (trust me!) So unpack and organise as early as you can before new baby is here. Again enlist friends and family to help (and make them help, rather than them coming over, doing 10 mins then having a tea and leaving
)
Remember to book internet connectivity ASAP and arrange all new direct debits, council tax etc before baby is born.
If I think of anything else I'll let you know! Congrats and good luck!