The larger stack has stored it all and given us the confidence to leave the grid charge button switched off on the hybrid inverter. I know for sure that I'd have been tapping the grid by now in smaller stack times.
We are averaging 0.75kWh per day from grid and most of that is down to us. At 07.30hrs today in cloud cover we have 1.5kW incoming and 39% soc. The HWT is fully charged and there are 70 miles on EV.
Having run through the house multiple times over the years to reduce power we are now in a magic place. Just coming up to our 6 yr anniversary since first panels installed.
The bigger battery though, absolutely pivotal in this endeavor.
The DPD driver was bemoaning the fact that all the heavy boxes were at the start of the day 
Thanks Colin. There are some much appreciated improvements to the packaging. Last time, the bolts and busbars did start little journeys around the packaging. Also, some serious contortions were required to get some of the batteries out of the foam. This time all the bolts/busbars are in a little packet keeping them together and the batteries are in little sleeves that makes them infinitely easier to remove from the foam. I've just disconnected all the Pylontech since they were just above 50% and am now slowly building the remaining stacks. Lots of crimping still do to, but at least all the wires are cut to the right lengths already.