That's a lot of power to expect to get from a facility.
Not as bad as many of the saw cutting machines but yes a pita to find a place to tie it in (safely) for a few hours.
I was very glad when more of the demo companies we work with started bringing a genset to run their equipment.
On the other hand I am very glad to see a brokk when it is 1AM, we have unwired display cases and are waiting on the demo guys to finish so we can do our new work.
For us a typical supermarket overnight goes like this.
Get to the store before close, get stuff out of the truck and ready, as soon as store closes we are running trying to unwire the cases as quickly as we can.
And then we sit and twiddle our thumbs waiting for the other trades, hopefully by 2 or 3 AM we can start wiring the new stuff, test it, get it down to temperature all by 7AM. Its one of those deals where more guys does not really help because all the trades, demo, carpenters, pipefitters, plumbers, floor tile guys and electricians are standing on each other.