The guy I used to work with simply just skipped the windows, he mainly paid attention to what time he was showing up to avoid the morning-lunch-dinner times. He’d still clean the window if a customer moved, but he didn’t stress about missing a pane or two.
Another window cleaner I used to work with used to bring in a jug of ammonia and pour it into a separate bucket to clear the room out when he was doing the inside of high rise buildings. I don’t think the big high rise building maintenance contractors were as worried about customer service.
So this may be a little lazy but after I do what I can (using the same techniques as were already mentioned) I let the waitresses and hostess know what booths I still need to get and then sit at the counter and have a cup of coffee. Normally they comp the coffee, I leave a tip and when I am done with my Coffey break those tables are empty.