I've done the following about 6 times in the last 6 months with no noticeable problems: Mash/run-off late afternoon or evening, put the wort (~15 gals) into a brute barrel in a walk-in cooler at around 8 or 9 pm, then start the boil the next morning at 8 or 9am. Never heated to 180F as majorvices suggests, and never had any souring or weirdness. Wort temp in the morning usually high 30s.
But you want to do a longer pause in the action, and it might still work, if you can get the wort temp down below 40F where bacterial growth is greatly inhibited (although not completely stopped). I certainly wouldn't leave the wort at 65F or 85F.