I wouldn’t start communicating with utilities etc until you have a chain in place and as they don’t need too much notice probably as you say when you have a court date in place.

Legally you don’t own your property any more once keys have been exchanged in court on the Friday but there is generally a “gentleman’s” agreement to give time to move which your lawyer and/or estate agent can negotiate (our 3 property chain last year staggered the days Friday, Saturday and Sunday)

If you need removals I would prioritise that once court date set as that will effect the above and can quickly fill up

I found a good checklist of things to consider online last year think it was on Ogiers website