The problem with asking him to go to the pub is that you won’t know how long he’s away.
Whereas if you get someone in your family to ask him to help with some DIY etc you will know he’s safely occupied. And in the event that he leaves their house early, They will call you so you get advance warning.
Then you won’t be terrified all the time that he could turn up at home.
Ideally you want him to be at their house doing DIY and then for then to suggest a couple of pints at the local / in the back garden to reward themselves. That will delay him even longer as he can’t drive home for a few hours.
It doesn’t matter about you making them an accessory, he will find out anyway later because the younger kids will tell him that your sisters helped with the move.
I’d also echo a PPs suggestion that you get more stuff out the house now under the pretence of clearing out to the charity shop. Take anything he won’t notice, like your and the kids winter clothes, toys they don’t play with much right now, spare sets of bedding and towels, anything in the loft / shed / garage if you have one.
Do your kids have younger cousins that they could “ give “ some of their toys to that they have “ outgrown “?
Anything you can do now will save time on the day. It takes much mother than you think to clear everything. It’s not the obvious stuff like clothes, it’s the things you never think of like the bathroom cabinet with all your toiletries and meds, spare bedding and towels, tools for DIY, the mounds of toys, contents of the kitchen cupboard.
I know none of these things are essential to life but they are expensive and time consuming to replace. It’s also very important for the kids to feel at home in their new house if they Have as much of their own stuff as possible.
Does your husband ever complain about the meds in teh house or too many toys everywhere ? This is a great chance to tell him that you’ve thought about what he said and realised he’s right and that you do need to clear out / get the kids to tidy their bedrooms.
Remember that on leaving day you need to take mobile phones away from the younger kids, In case they phone their dad / he phones them and they blurt it out.