In theory, you could go over the car with QD without washing but I'd be too worried about inflicting swirls.
There's a huge difference between overnight and a week - you still get a helluva lot of pollution.
I keep my car in the garage, so less crap on it if washed the night before.
Honestly, it'd take at max an hour to snow foam the car, power rinse it, dry it and apply Red Mist. If you'd started at 0800, you'd have been done by now.